diff --git a/src/LibHac/Fs/SaveDataStructs.cs b/src/LibHac/Fs/SaveDataStructs.cs
index 8ac01c43..ed13769a 100644
--- a/src/LibHac/Fs/SaveDataStructs.cs
+++ b/src/LibHac/Fs/SaveDataStructs.cs
@@ -15,12 +15,31 @@ namespace LibHac.Fs
         [FieldOffset(0x21)] public SaveDataRank Rank;
         [FieldOffset(0x22)] public short Index;
 
-        public override bool Equals(object obj)
+        public SaveDataAttribute(ProgramId programId, SaveDataType type, UserId userId, ulong saveDataId) : this(
+            programId, type, userId, saveDataId, 0, SaveDataRank.Primary)
+        { }
+
+        public SaveDataAttribute(ProgramId programId, SaveDataType type, UserId userId, ulong saveDataId,
+            short index) : this(programId, type, userId, saveDataId, index, SaveDataRank.Primary)
+        { }
+
+        public SaveDataAttribute(ProgramId programId, SaveDataType type, UserId userId, ulong saveDataId, short index,
+            SaveDataRank rank)
+        {
+            ProgramId = programId;
+            Type = type;
+            UserId = userId;
+            StaticSaveDataId = saveDataId;
+            Index = index;
+            Rank = rank;
+        }
+
+        public override readonly bool Equals(object obj)
         {
             return obj is SaveDataAttribute attribute && Equals(attribute);
         }
 
-        public bool Equals(SaveDataAttribute other)
+        public readonly bool Equals(SaveDataAttribute other)
         {
             return ProgramId == other.ProgramId &&
                    Type == other.Type &&
@@ -33,24 +52,24 @@ namespace LibHac.Fs
         public static bool operator ==(SaveDataAttribute left, SaveDataAttribute right) => left.Equals(right);
         public static bool operator !=(SaveDataAttribute left, SaveDataAttribute right) => !(left == right);
 
-        public override int GetHashCode()
+        public override readonly int GetHashCode()
         {
             // ReSharper disable NonReadonlyMemberInGetHashCode
             return HashCode.Combine(ProgramId, Type, UserId, StaticSaveDataId, Rank, Index);
             // ReSharper restore NonReadonlyMemberInGetHashCode
         }
 
-        public int CompareTo(SaveDataAttribute other)
+        public readonly int CompareTo(SaveDataAttribute other)
         {
             int titleIdComparison = ProgramId.CompareTo(other.ProgramId);
             if (titleIdComparison != 0) return titleIdComparison;
-            int typeComparison = Type.CompareTo(other.Type);
+            int typeComparison = ((int)Type).CompareTo((int)other.Type);
             if (typeComparison != 0) return typeComparison;
             int userIdComparison = UserId.CompareTo(other.UserId);
             if (userIdComparison != 0) return userIdComparison;
             int saveDataIdComparison = StaticSaveDataId.CompareTo(other.StaticSaveDataId);
             if (saveDataIdComparison != 0) return saveDataIdComparison;
-            int rankComparison = Rank.CompareTo(other.Rank);
+            int rankComparison = ((int)Rank).CompareTo((int)other.Rank);
             if (rankComparison != 0) return rankComparison;
             return Index.CompareTo(other.Index);
         }
diff --git a/src/LibHac/Fs/Shim/BcatSaveData.cs b/src/LibHac/Fs/Shim/BcatSaveData.cs
index c89cf6d2..95c27611 100644
--- a/src/LibHac/Fs/Shim/BcatSaveData.cs
+++ b/src/LibHac/Fs/Shim/BcatSaveData.cs
@@ -43,9 +43,7 @@ namespace LibHac.Fs.Shim
 
             IFileSystemProxy fsProxy = fs.GetFileSystemProxyServiceObject();
 
-            SaveDataAttribute attribute = default;
-            attribute.ProgramId = applicationId;
-            attribute.Type = SaveDataType.Bcat;
+            var attribute = new SaveDataAttribute(applicationId, SaveDataType.Bcat, UserId.Zero, 0);
 
             rc = fsProxy.OpenSaveDataFileSystem(out IFileSystem fileSystem, SaveDataSpaceId.User, ref attribute);
             if (rc.IsFailure()) return rc;
diff --git a/src/LibHac/Fs/Shim/SaveData.cs b/src/LibHac/Fs/Shim/SaveData.cs
index b7e8eecb..b641906c 100644
--- a/src/LibHac/Fs/Shim/SaveData.cs
+++ b/src/LibHac/Fs/Shim/SaveData.cs
@@ -191,11 +191,7 @@ namespace LibHac.Fs.Shim
 
             IFileSystemProxy fsProxy = fs.GetFileSystemProxyServiceObject();
 
-            SaveDataAttribute attribute = default;
-            attribute.ProgramId = programId;
-            attribute.UserId = userId;
-            attribute.Type = type;
-            attribute.Index = index;
+            var attribute = new SaveDataAttribute(programId, type, userId, 0, index);
 
             IFileSystem saveFs;
 
diff --git a/src/LibHac/Fs/Shim/SaveDataManagement.cs b/src/LibHac/Fs/Shim/SaveDataManagement.cs
index 59602fbd..9e972867 100644
--- a/src/LibHac/Fs/Shim/SaveDataManagement.cs
+++ b/src/LibHac/Fs/Shim/SaveDataManagement.cs
@@ -17,12 +17,7 @@ namespace LibHac.Fs.Shim
                 {
                     IFileSystemProxy fsProxy = fs.GetFileSystemProxyServiceObject();
 
-                    var attribute = new SaveDataAttribute
-                    {
-                        ProgramId = applicationId,
-                        UserId = userId,
-                        Type = SaveDataType.Account
-                    };
+                    var attribute = new SaveDataAttribute(applicationId, SaveDataType.Account, userId, 0);
 
                     var createInfo = new SaveDataCreationInfo
                     {
@@ -54,12 +49,7 @@ namespace LibHac.Fs.Shim
                 {
                     IFileSystemProxy fsProxy = fs.GetFileSystemProxyServiceObject();
 
-                    var attribute = new SaveDataAttribute
-                    {
-                        ProgramId = applicationId,
-                        UserId = userId,
-                        Type = SaveDataType.Account
-                    };
+                    var attribute = new SaveDataAttribute(applicationId, SaveDataType.Account, userId, 0);
 
                     var createInfo = new SaveDataCreationInfo
                     {
@@ -91,11 +81,7 @@ namespace LibHac.Fs.Shim
                 {
                     IFileSystemProxy fsProxy = fs.GetFileSystemProxyServiceObject();
 
-                    var attribute = new SaveDataAttribute
-                    {
-                        ProgramId = applicationId,
-                        Type = SaveDataType.Bcat
-                    };
+                    var attribute = new SaveDataAttribute(applicationId, SaveDataType.Bcat, UserId.Zero, 0);
 
                     var createInfo = new SaveDataCreationInfo
                     {
@@ -122,11 +108,7 @@ namespace LibHac.Fs.Shim
                 {
                     IFileSystemProxy fsProxy = fs.GetFileSystemProxyServiceObject();
 
-                    var attribute = new SaveDataAttribute
-                    {
-                        ProgramId = applicationId,
-                        Type = SaveDataType.Device
-                    };
+                    var attribute = new SaveDataAttribute(applicationId, SaveDataType.Device, UserId.Zero, 0);
 
                     var createInfo = new SaveDataCreationInfo
                     {
@@ -152,11 +134,7 @@ namespace LibHac.Fs.Shim
                 {
                     IFileSystemProxy fsProxy = fs.GetFileSystemProxyServiceObject();
 
-                    var attribute = new SaveDataAttribute
-                    {
-                        ProgramId = applicationId,
-                        Type = SaveDataType.Temporary
-                    };
+                    var attribute = new SaveDataAttribute(applicationId, SaveDataType.Temporary, UserId.Zero, 0);
 
                     var createInfo = new SaveDataCreationInfo
                     {
@@ -182,12 +160,7 @@ namespace LibHac.Fs.Shim
                 {
                     IFileSystemProxy fsProxy = fs.GetFileSystemProxyServiceObject();
 
-                    var attribute = new SaveDataAttribute
-                    {
-                        ProgramId = applicationId,
-                        Type = SaveDataType.Cache,
-                        Index = index
-                    };
+                    var attribute = new SaveDataAttribute(applicationId, SaveDataType.Cache, UserId.Zero, 0, index);
 
                     var creationInfo = new SaveDataCreationInfo
                     {
@@ -226,11 +199,7 @@ namespace LibHac.Fs.Shim
                 {
                     IFileSystemProxy fsProxy = fs.GetFileSystemProxyServiceObject();
 
-                    var attribute = new SaveDataAttribute
-                    {
-                        UserId = userId,
-                        StaticSaveDataId = saveDataId
-                    };
+                    var attribute = new SaveDataAttribute(ProgramId.InvalidId, SaveDataType.System, userId, saveDataId);
 
                     var createInfo = new SaveDataCreationInfo
                     {
diff --git a/src/LibHac/Fs/Shim/SystemSaveData.cs b/src/LibHac/Fs/Shim/SystemSaveData.cs
index 838db618..b817ad07 100644
--- a/src/LibHac/Fs/Shim/SystemSaveData.cs
+++ b/src/LibHac/Fs/Shim/SystemSaveData.cs
@@ -1,6 +1,7 @@
 using LibHac.Common;
 using LibHac.Fs.Fsa;
 using LibHac.FsService;
+using LibHac.Ncm;
 
 namespace LibHac.Fs.Shim
 {
@@ -19,9 +20,7 @@ namespace LibHac.Fs.Shim
 
             IFileSystemProxy fsProxy = fs.GetFileSystemProxyServiceObject();
 
-            SaveDataAttribute attribute = default;
-            attribute.UserId = userId;
-            attribute.StaticSaveDataId = saveDataId;
+            var attribute = new SaveDataAttribute(ProgramId.InvalidId, SaveDataType.System, userId, saveDataId);
 
             rc = fsProxy.OpenSaveDataFileSystemBySystemSaveDataId(out IFileSystem fileSystem, spaceId, ref attribute);
             if (rc.IsFailure()) return rc;
diff --git a/src/LibHac/FsService/FileSystemProxy.cs b/src/LibHac/FsService/FileSystemProxy.cs
index bec3acfd..3f3eaf95 100644
--- a/src/LibHac/FsService/FileSystemProxy.cs
+++ b/src/LibHac/FsService/FileSystemProxy.cs
@@ -227,7 +227,7 @@ namespace LibHac.FsService
             return DeleteSaveDataFileSystemImpl(spaceId, saveDataId);
         }
 
-        private Result GetSaveDataInfo(out SaveDataInfo info, SaveDataSpaceId spaceId, ref SaveDataAttribute attribute)
+        private Result GetSaveDataInfo(out SaveDataInfo info, SaveDataSpaceId spaceId, in SaveDataAttribute attribute)
         {
             Unsafe.SkipInit(out info);
 
@@ -236,7 +236,7 @@ namespace LibHac.FsService
 
             using (accessor)
             {
-                rc = accessor.Indexer.Get(out SaveDataIndexerValue value, ref attribute);
+                rc = accessor.Indexer.Get(out SaveDataIndexerValue value, in attribute);
                 if (rc.IsFailure()) return rc;
 
                 SaveDataIndexer.GenerateSaveDataInfo(out info, in attribute, in value);
@@ -246,7 +246,7 @@ namespace LibHac.FsService
 
         public Result DeleteSaveDataFileSystemBySaveDataAttribute(SaveDataSpaceId spaceId, ref SaveDataAttribute attribute)
         {
-            Result rs = GetSaveDataInfo(out SaveDataInfo info, spaceId, ref attribute);
+            Result rs = GetSaveDataInfo(out SaveDataInfo info, spaceId, in attribute);
             if (rs.IsFailure()) return rs;
 
             return DeleteSaveDataFileSystemBySaveDataSpaceIdImpl(spaceId, info.SaveDataId);
@@ -291,7 +291,7 @@ namespace LibHac.FsService
                     {
                         saveDataId = attribute.StaticSaveDataId;
 
-                        rc = accessor.Indexer.PutStaticSaveDataIdIndex(ref indexerKey);
+                        rc = accessor.Indexer.PutStaticSaveDataIdIndex(in indexerKey);
                     }
                     else
                     {
@@ -304,7 +304,7 @@ namespace LibHac.FsService
                             }
                         }
 
-                        rc = accessor.Indexer.Publish(out saveDataId, ref indexerKey);
+                        rc = accessor.Indexer.Publish(out saveDataId, in indexerKey);
                     }
 
                     if (ResultFs.SaveDataPathAlreadyExists.Includes(rc))
@@ -491,7 +491,7 @@ namespace LibHac.FsService
                 using SaveDataIndexerAccessor accessor = tempAccessor;
                 if (rc.IsFailure()) return rc;
 
-                rc = accessor.Indexer.Get(out SaveDataIndexerValue indexerValue, ref indexerKey);
+                rc = accessor.Indexer.Get(out SaveDataIndexerValue indexerValue, in indexerKey);
                 if (rc.IsFailure()) return rc;
 
                 SaveDataSpaceId indexerSpaceId = GetSpaceIdForIndexer(spaceId);
@@ -1143,9 +1143,8 @@ namespace LibHac.FsService
         {
             fileSystem = default;
 
-            SaveDataAttribute attribute = default;
-            attribute.ProgramId = new ProgramId(MultiCommitManager.ProgramId);
-            attribute.StaticSaveDataId = MultiCommitManager.SaveDataId;
+            var attribute = new SaveDataAttribute(new ProgramId(MultiCommitManager.ProgramId), SaveDataType.System,
+                UserId.Zero, MultiCommitManager.SaveDataId);
 
             Result rc = OpenSaveDataFileSystemImpl(out IFileSystem saveFs, out _, SaveDataSpaceId.System, ref attribute,
                 false, true);
diff --git a/src/LibHac/FsService/ISaveDataIndexer.cs b/src/LibHac/FsService/ISaveDataIndexer.cs
index ea618a87..f98eb759 100644
--- a/src/LibHac/FsService/ISaveDataIndexer.cs
+++ b/src/LibHac/FsService/ISaveDataIndexer.cs
@@ -8,9 +8,9 @@ namespace LibHac.FsService
         Result Commit();
         Result Rollback();
         Result Reset();
-        Result Publish(out ulong saveDataId, ref SaveDataAttribute key);
-        Result Get(out SaveDataIndexerValue value, ref SaveDataAttribute key);
-        Result PutStaticSaveDataIdIndex(ref SaveDataAttribute key);
+        Result Publish(out ulong saveDataId, in SaveDataAttribute key);
+        Result Get(out SaveDataIndexerValue value, in SaveDataAttribute key);
+        Result PutStaticSaveDataIdIndex(in SaveDataAttribute key);
         bool IsRemainedReservedOnly();
         Result Delete(ulong saveDataId);
         Result SetSpaceId(ulong saveDataId, SaveDataSpaceId spaceId);
@@ -18,7 +18,7 @@ namespace LibHac.FsService
         Result SetState(ulong saveDataId, SaveDataState state);
         Result GetKey(out SaveDataAttribute key, ulong saveDataId);
         Result GetValue(out SaveDataIndexerValue value, ulong saveDataId);
-        Result SetValue(ref SaveDataAttribute key, ref SaveDataIndexerValue value);
+        Result SetValue(in SaveDataAttribute key, in SaveDataIndexerValue value);
         int GetIndexCount();
         Result OpenSaveDataInfoReader(out ReferenceCountedDisposable<ISaveDataInfoReader> infoReader);
     }
diff --git a/src/LibHac/FsService/SaveDataIndexer.cs b/src/LibHac/FsService/SaveDataIndexer.cs
index b1dd3913..fc24b9f4 100644
--- a/src/LibHac/FsService/SaveDataIndexer.cs
+++ b/src/LibHac/FsService/SaveDataIndexer.cs
@@ -197,7 +197,7 @@ namespace LibHac.FsService
             }
         }
 
-        public Result Publish(out ulong saveDataId, ref SaveDataAttribute key)
+        public Result Publish(out ulong saveDataId, in SaveDataAttribute key)
         {
             saveDataId = default;
 
@@ -212,7 +212,7 @@ namespace LibHac.FsService
                 Unsafe.SkipInit(out SaveDataIndexerValue value);
 
                 // Make sure the key isn't in the database already.
-                rc = KvDatabase.Get(out _, ref key, SpanHelpers.AsByteSpan(ref value));
+                rc = KvDatabase.Get(out _, in key, SpanHelpers.AsByteSpan(ref value));
 
                 if (rc.IsSuccess())
                 {
@@ -224,7 +224,7 @@ namespace LibHac.FsService
 
                 value = new SaveDataIndexerValue { SaveDataId = newSaveDataId };
 
-                rc = KvDatabase.Set(ref key, SpanHelpers.AsByteSpan(ref value));
+                rc = KvDatabase.Set(in key, SpanHelpers.AsByteSpan(ref value));
 
                 if (rc.IsFailure())
                 {
@@ -232,7 +232,7 @@ namespace LibHac.FsService
                     return rc;
                 }
 
-                rc = FixReader(ref key);
+                rc = FixReader(in key);
                 if (rc.IsFailure()) return rc;
 
                 saveDataId = newSaveDataId;
@@ -240,7 +240,7 @@ namespace LibHac.FsService
             }
         }
 
-        public Result Get(out SaveDataIndexerValue value, ref SaveDataAttribute key)
+        public Result Get(out SaveDataIndexerValue value, in SaveDataAttribute key)
         {
             Unsafe.SkipInit(out value);
 
@@ -252,7 +252,7 @@ namespace LibHac.FsService
                 rc = TryLoadDatabase(false);
                 if (rc.IsFailure()) return rc;
 
-                rc = KvDatabase.Get(out _, ref key, SpanHelpers.AsByteSpan(ref value));
+                rc = KvDatabase.Get(out _, in key, SpanHelpers.AsByteSpan(ref value));
 
                 if (rc.IsFailure())
                 {
@@ -263,7 +263,7 @@ namespace LibHac.FsService
             }
         }
 
-        public Result PutStaticSaveDataIdIndex(ref SaveDataAttribute key)
+        public Result PutStaticSaveDataIdIndex(in SaveDataAttribute key)
         {
             lock (Locker)
             {
@@ -290,10 +290,10 @@ namespace LibHac.FsService
                     SaveDataId = key.StaticSaveDataId
                 };
 
-                rc = KvDatabase.Set(ref key, SpanHelpers.AsReadOnlyByteSpan(in newValue));
+                rc = KvDatabase.Set(in key, SpanHelpers.AsReadOnlyByteSpan(in newValue));
                 if (rc.IsFailure()) return rc;
 
-                rc = FixReader(ref key);
+                rc = FixReader(in key);
                 if (rc.IsFailure()) return rc;
 
                 return Result.Success;
@@ -330,10 +330,10 @@ namespace LibHac.FsService
 
                 SaveDataAttribute key = iterator.Get().Key;
 
-                rc = KvDatabase.Delete(ref key);
+                rc = KvDatabase.Delete(in key);
                 if (rc.IsFailure()) return rc;
 
-                rc = FixReader(ref key);
+                rc = FixReader(in key);
                 if (rc.IsFailure()) return rc;
 
                 return Result.Success;
@@ -371,7 +371,7 @@ namespace LibHac.FsService
 
                 func(ref value, data);
 
-                rc = KvDatabase.Set(ref iterator.Get().Key, SpanHelpers.AsReadOnlyByteSpan(in value));
+                rc = KvDatabase.Set(in iterator.Get().Key, SpanHelpers.AsReadOnlyByteSpan(in value));
                 if (rc.IsFailure()) return rc;
 
                 return Result.Success;
@@ -462,7 +462,7 @@ namespace LibHac.FsService
             return ResultFs.TargetNotFound.Log();
         }
 
-        public Result SetValue(ref SaveDataAttribute key, ref SaveDataIndexerValue value)
+        public Result SetValue(in SaveDataAttribute key, in SaveDataIndexerValue value)
         {
             Result rc = TryInitializeDatabase();
             if (rc.IsFailure()) return rc;
@@ -470,7 +470,7 @@ namespace LibHac.FsService
             rc = TryLoadDatabase(false);
             if (rc.IsFailure()) return rc;
 
-            FlatMapKeyValueStore<SaveDataAttribute>.Iterator iterator = KvDatabase.GetLowerBoundIterator(ref key);
+            FlatMapKeyValueStore<SaveDataAttribute>.Iterator iterator = KvDatabase.GetLowerBoundIterator(in key);
 
             // Key was not found
             if (iterator.IsEnd())
@@ -520,9 +520,9 @@ namespace LibHac.FsService
         }
 
         private void FixIterator(ref FlatMapKeyValueStore<SaveDataAttribute>.Iterator iterator,
-            ref SaveDataAttribute key)
+            in SaveDataAttribute key)
         {
-            KvDatabase.FixIterator(ref iterator, ref key);
+            KvDatabase.FixIterator(ref iterator, in key);
         }
 
         /// <summary>
@@ -688,13 +688,13 @@ namespace LibHac.FsService
         /// </summary>
         /// <param name="key">The key of the element that was removed or added.</param>
         /// <returns>The <see cref="Result"/> of the operation.</returns>
-        private Result FixReader(ref SaveDataAttribute key)
+        private Result FixReader(in SaveDataAttribute key)
         {
             foreach (ReaderAccessor accessor in OpenReaders)
             {
                 using (ReferenceCountedDisposable<Reader> reader = accessor.Lock())
                 {
-                    reader?.Target.Fix(ref key);
+                    reader?.Target.Fix(in key);
                 }
             }
 
@@ -826,9 +826,9 @@ namespace LibHac.FsService
                 }
             }
 
-            public void Fix(ref SaveDataAttribute attribute)
+            public void Fix(in SaveDataAttribute attribute)
             {
-                _indexer.FixIterator(ref _iterator, ref attribute);
+                _indexer.FixIterator(ref _iterator, in attribute);
             }
 
             public void Dispose()
diff --git a/src/LibHac/FsService/SaveDataIndexerLite.cs b/src/LibHac/FsService/SaveDataIndexerLite.cs
index 040ccedb..855526c2 100644
--- a/src/LibHac/FsService/SaveDataIndexerLite.cs
+++ b/src/LibHac/FsService/SaveDataIndexerLite.cs
@@ -32,7 +32,7 @@ namespace LibHac.FsService
             }
         }
 
-        public Result Publish(out ulong saveDataId, ref SaveDataAttribute key)
+        public Result Publish(out ulong saveDataId, in SaveDataAttribute key)
         {
             lock (Locker)
             {
@@ -53,7 +53,7 @@ namespace LibHac.FsService
             }
         }
 
-        public Result Get(out SaveDataIndexerValue value, ref SaveDataAttribute key)
+        public Result Get(out SaveDataIndexerValue value, in SaveDataAttribute key)
         {
             lock (Locker)
             {
@@ -68,7 +68,7 @@ namespace LibHac.FsService
             }
         }
 
-        public Result PutStaticSaveDataIdIndex(ref SaveDataAttribute key)
+        public Result PutStaticSaveDataIdIndex(in SaveDataAttribute key)
         {
             lock (Locker)
             {
@@ -179,7 +179,7 @@ namespace LibHac.FsService
             }
         }
 
-        public Result SetValue(ref SaveDataAttribute key, ref SaveDataIndexerValue value)
+        public Result SetValue(in SaveDataAttribute key, in SaveDataIndexerValue value)
         {
             lock (Locker)
             {
@@ -235,7 +235,7 @@ namespace LibHac.FsService
             {
                 Span<SaveDataInfo> outInfo = MemoryMarshal.Cast<byte, SaveDataInfo>(saveDataInfoBuffer);
 
-                // Note: Nintendo doesn't check if the buffer is too small here
+                // Note: Nintendo doesn't check if the buffer is large enough here
                 if (_finishedIterating || outInfo.IsEmpty)
                 {
                     readCount = 0;
diff --git a/src/LibHac/Kvdb/FlatMapKeyValueStore.cs b/src/LibHac/Kvdb/FlatMapKeyValueStore.cs
index dbeb2211..6c92b7b7 100644
--- a/src/LibHac/Kvdb/FlatMapKeyValueStore.cs
+++ b/src/LibHac/Kvdb/FlatMapKeyValueStore.cs
@@ -154,12 +154,12 @@ namespace LibHac.Kvdb
         /// <remarks>Possible <see cref="Result"/>s:<br/>
         /// <see cref="ResultKvdb.KeyNotFound"/>
         /// The specified key was not found in the <see cref="FlatMapKeyValueStore{T}"/>.</remarks>
-        public Result Get(out int valueSize, ref TKey key, Span<byte> valueBuffer)
+        public Result Get(out int valueSize, in TKey key, Span<byte> valueBuffer)
         {
             Unsafe.SkipInit(out valueSize);
 
             // Find entry.
-            ConstIterator iterator = _index.GetLowerBoundConstIterator(ref key);
+            ConstIterator iterator = _index.GetLowerBoundConstIterator(in key);
             if (iterator.IsEnd())
                 return ResultKvdb.KeyNotFound.Log();
 
@@ -182,9 +182,9 @@ namespace LibHac.Kvdb
         /// <param name="key">The key to add.</param>
         /// <param name="value">The value to add.</param>
         /// <returns>The <see cref="Result"/> of the operation.</returns>
-        public Result Set(ref TKey key, ReadOnlySpan<byte> value)
+        public Result Set(in TKey key, ReadOnlySpan<byte> value)
         {
-            return _index.Set(ref key, value);
+            return _index.Set(in key, value);
         }
 
         /// <summary>
@@ -195,9 +195,9 @@ namespace LibHac.Kvdb
         /// <remarks>Possible <see cref="Result"/>s:<br/>
         /// <see cref="ResultKvdb.KeyNotFound"/>
         /// The specified key was not found in the <see cref="FlatMapKeyValueStore{T}"/>.</remarks>
-        public Result Delete(ref TKey key)
+        public Result Delete(in TKey key)
         {
-            if (!_index.Delete(ref key))
+            if (!_index.Delete(in key))
                 return ResultKvdb.KeyNotFound.Log();
 
             return Result.Success;
@@ -218,9 +218,9 @@ namespace LibHac.Kvdb
         /// </summary>
         /// <param name="key">The key at which to begin iteration.</param>
         /// <returns>The created iterator.</returns>
-        public Iterator GetLowerBoundIterator(ref TKey key)
+        public Iterator GetLowerBoundIterator(in TKey key)
         {
-            return _index.GetLowerBoundIterator(ref key);
+            return _index.GetLowerBoundIterator(in key);
         }
 
         /// <summary>
@@ -229,9 +229,9 @@ namespace LibHac.Kvdb
         /// </summary>
         /// <param name="iterator">The iterator to fix.</param>
         /// <param name="key">The key that was added or removed.</param>
-        public void FixIterator(ref Iterator iterator, ref TKey key)
+        public void FixIterator(ref Iterator iterator, in TKey key)
         {
-            _index.FixIterator(ref iterator, ref key);
+            _index.FixIterator(ref iterator, in key);
         }
 
         /// <summary>
@@ -296,7 +296,7 @@ namespace LibHac.Kvdb
                     rc = reader.ReadKeyValue(SpanHelpers.AsByteSpan(ref key), newValue.Get());
                     if (rc.IsFailure()) return rc;
 
-                    rc = _index.AppendUnsafe(ref key, newValue);
+                    rc = _index.AppendUnsafe(in key, newValue);
                     if (rc.IsFailure()) return rc;
 
                     success = true;
@@ -377,7 +377,7 @@ namespace LibHac.Kvdb
             public TKey Key;
             public MemoryResource.Buffer Value;
 
-            public KeyValue(ref TKey key, MemoryResource.Buffer value)
+            public KeyValue(in TKey key, MemoryResource.Buffer value)
             {
                 Key = key;
                 Value = value;
@@ -437,10 +437,10 @@ namespace LibHac.Kvdb
             /// <param name="key">The key to add.</param>
             /// <param name="value">The value to add.</param>
             /// <returns>The <see cref="Result"/> of the operation.</returns>
-            public Result Set(ref TKey key, ReadOnlySpan<byte> value)
+            public Result Set(in TKey key, ReadOnlySpan<byte> value)
             {
                 // The list is sorted by key. Find the index to insert at.
-                int index = GetLowerBoundIndex(ref key);
+                int index = GetLowerBoundIndex(in key);
 
                 if (index != _count && _entries[index].Key.Equals(key))
                 {
@@ -465,7 +465,7 @@ namespace LibHac.Kvdb
                 value.CopyTo(newValue.Get());
 
                 // Add the new entry to the list.
-                _entries[index] = new KeyValue(ref key, newValue);
+                _entries[index] = new KeyValue(in key, newValue);
 
                 return Result.Success;
             }
@@ -478,7 +478,7 @@ namespace LibHac.Kvdb
             /// <param name="key">The key to add.</param>
             /// <param name="value">The value to add.</param>
             /// <returns>The <see cref="Result"/> of the operation.</returns>
-            public Result AppendUnsafe(ref TKey key, MemoryResource.Buffer value)
+            public Result AppendUnsafe(in TKey key, MemoryResource.Buffer value)
             {
                 if (_count >= _capacity)
                     return ResultKvdb.OutOfKeyResource.Log();
@@ -489,7 +489,7 @@ namespace LibHac.Kvdb
                     Assert.AssertTrue(key.CompareTo(_entries[_count - 1].Key) > 0);
                 }
 
-                _entries[_count] = new KeyValue(ref key, value);
+                _entries[_count] = new KeyValue(in key, value);
                 _count++;
 
                 return Result.Success;
@@ -516,9 +516,9 @@ namespace LibHac.Kvdb
             /// <param name="key">The key of the element to delete.</param>
             /// <returns><see langword="true"/> if the item was found and deleted.
             /// <see langword="false"/> if the key was not in the store.</returns>
-            public bool Delete(ref TKey key)
+            public bool Delete(in TKey key)
             {
-                int index = GetLowerBoundIndex(ref key);
+                int index = GetLowerBoundIndex(in key);
 
                 // Make sure the key was found.
                 if (index == _count || !_entries[index].Key.Equals(key))
@@ -558,9 +558,9 @@ namespace LibHac.Kvdb
             /// </summary>
             /// <param name="key">The key at which to begin iteration.</param>
             /// <returns>The created iterator.</returns>
-            public Iterator GetLowerBoundIterator(ref TKey key)
+            public Iterator GetLowerBoundIterator(in TKey key)
             {
-                int index = GetLowerBoundIndex(ref key);
+                int index = GetLowerBoundIndex(in key);
 
                 return new Iterator(_entries, index, _count);
             }
@@ -570,9 +570,9 @@ namespace LibHac.Kvdb
             /// </summary>
             /// <param name="key">The key at which to begin iteration.</param>
             /// <returns>The created iterator.</returns>
-            public ConstIterator GetLowerBoundConstIterator(ref TKey key)
+            public ConstIterator GetLowerBoundConstIterator(in TKey key)
             {
-                int index = GetLowerBoundIndex(ref key);
+                int index = GetLowerBoundIndex(in key);
 
                 return new ConstIterator(_entries, index, _count);
             }
@@ -583,31 +583,33 @@ namespace LibHac.Kvdb
             /// </summary>
             /// <param name="iterator">The iterator to fix.</param>
             /// <param name="key">The key that was added or removed.</param>
-            public void FixIterator(ref Iterator iterator, ref TKey key)
+            public void FixIterator(ref Iterator iterator, in TKey key)
             {
-                int keyIndex = GetLowerBoundIndex(ref key);
+                int keyIndex = GetLowerBoundIndex(in key);
                 iterator.Fix(keyIndex, _count);
             }
 
-            private int GetLowerBoundIndex(ref TKey key)
+            private int GetLowerBoundIndex(in TKey key)
             {
                 // The AsSpan takes care of any bounds checking
                 ReadOnlySpan<KeyValue> entries = _entries.AsSpan(0, _count);
 
-                return BinarySearch(ref MemoryMarshal.GetReference(entries), entries.Length, ref key);
+                return BinarySearch(ref MemoryMarshal.GetReference(entries), entries.Length, in key);
             }
 
-            private static int BinarySearch(ref KeyValue spanStart, int length, ref TKey item)
+            private static int BinarySearch(ref KeyValue spanStart, int length, in TKey item)
             {
                 // A tweaked version of .NET's SpanHelpers.BinarySearch
                 int lo = 0;
                 int hi = length - 1;
 
+                TKey tempItem = item;
+
                 while (lo <= hi)
                 {
                     int i = (int)(((uint)hi + (uint)lo) >> 1);
 
-                    int c = item.CompareTo(Unsafe.Add(ref spanStart, i).Key);
+                    int c = tempItem.CompareTo(Unsafe.Add(ref spanStart, i).Key);
                     if (c == 0)
                     {
                         return i;
diff --git a/tests/LibHac.Tests/Kvdb/FlatMapKeyValueStoreTests.cs b/tests/LibHac.Tests/Kvdb/FlatMapKeyValueStoreTests.cs
index 455d5dda..62b4b4c1 100644
--- a/tests/LibHac.Tests/Kvdb/FlatMapKeyValueStoreTests.cs
+++ b/tests/LibHac.Tests/Kvdb/FlatMapKeyValueStoreTests.cs
@@ -63,7 +63,7 @@ namespace LibHac.Tests.Kvdb
             {
                 for (TTest i = 0; i < count; i++)
                 {
-                    Result rc = kvStore.Set(ref i, values[i]);
+                    Result rc = kvStore.Set(in i, values[i]);
                     if (rc.IsFailure()) return rc;
                 }
             }
@@ -74,7 +74,7 @@ namespace LibHac.Tests.Kvdb
                 for (int i = 0; i < count; i++)
                 {
                     TTest index = rng.Next();
-                    Result rc = kvStore.Set(ref index, values[index]);
+                    Result rc = kvStore.Set(in index, values[index]);
                     if (rc.IsFailure()) return rc;
                 }
             }
@@ -191,7 +191,7 @@ namespace LibHac.Tests.Kvdb
             TTest key = 20;
             var value = new byte[20];
 
-            Result rc = kvStore.Get(out int _, ref key, value);
+            Result rc = kvStore.Get(out int _, in key, value);
             Assert.Result(ResultKvdb.KeyNotFound, rc);
         }
 
@@ -210,7 +210,7 @@ namespace LibHac.Tests.Kvdb
 
             for (TTest i = 0; i < count; i++)
             {
-                Assert.Success(kvStore.Get(out int valueSize, ref i, value));
+                Assert.Success(kvStore.Get(out int valueSize, in i, value));
                 Assert.Equal(startingValueSize + i, valueSize);
             }
         }
@@ -231,7 +231,7 @@ namespace LibHac.Tests.Kvdb
             for (int i = 0; i < count; i++)
             {
                 TTest key = i;
-                Assert.Success(kvStore.Get(out int _, ref key, value));
+                Assert.Success(kvStore.Get(out int _, in key, value));
                 Assert.Equal(values[i], value.AsSpan(0, startingValueSize + i).ToArray());
             }
         }
@@ -246,7 +246,7 @@ namespace LibHac.Tests.Kvdb
             Assert.Success(PopulateKvStore(kvStore, out byte[][] values, count));
 
             TTest key = count;
-            Result rc = kvStore.Set(ref key, values[0]);
+            Result rc = kvStore.Set(in key, values[0]);
 
             Assert.Result(ResultKvdb.OutOfKeyResource, rc);
         }
@@ -266,11 +266,11 @@ namespace LibHac.Tests.Kvdb
             var value = new byte[15];
             value.AsSpan().Fill(0xFF);
 
-            Assert.Success(kvStore.Set(ref key, value));
+            Assert.Success(kvStore.Set(in key, value));
 
             // Read back the value
             var readValue = new byte[20];
-            Assert.Success(kvStore.Get(out int valueSize, ref key, readValue));
+            Assert.Success(kvStore.Get(out int valueSize, in key, readValue));
 
             // Check the value contents and size
             Assert.Equal(value.Length, valueSize);
@@ -314,7 +314,7 @@ namespace LibHac.Tests.Kvdb
 
             (FlatMapKeyValueStore<TTest> kvStore, FileSystemClient _) = Create<TTest>(count);
 
-            Result rc = kvStore.Delete(ref keyToDelete);
+            Result rc = kvStore.Delete(in keyToDelete);
             Assert.Result(ResultKvdb.KeyNotFound, rc);
         }
 
@@ -327,7 +327,7 @@ namespace LibHac.Tests.Kvdb
             (FlatMapKeyValueStore<TTest> kvStore, FileSystemClient _) = Create<TTest>(count);
             Assert.Success(PopulateKvStore(kvStore, out _, count));
 
-            Result rc = kvStore.Delete(ref keyToDelete);
+            Result rc = kvStore.Delete(in keyToDelete);
             Assert.Result(ResultKvdb.KeyNotFound, rc);
         }
 
@@ -345,11 +345,11 @@ namespace LibHac.Tests.Kvdb
             Assert.Success(PopulateKvStore(kvStore, out _, count, startingValueSize, rngSeed));
 
             TTest keyToDelete = entryToDelete;
-            Assert.Success(kvStore.Delete(ref keyToDelete));
+            Assert.Success(kvStore.Delete(in keyToDelete));
 
             var value = new byte[20];
 
-            Result rc = kvStore.Get(out int _, ref keyToDelete, value);
+            Result rc = kvStore.Get(out int _, in keyToDelete, value);
             Assert.Result(ResultKvdb.KeyNotFound, rc);
         }
 
@@ -365,7 +365,7 @@ namespace LibHac.Tests.Kvdb
             Assert.Success(PopulateKvStore(kvStore, out _, count));
 
             TTest keyToDelete = entryToDelete;
-            Assert.Success(kvStore.Delete(ref keyToDelete));
+            Assert.Success(kvStore.Delete(in keyToDelete));
 
             Assert.Equal(count - 1, kvStore.Count);
         }
@@ -382,7 +382,7 @@ namespace LibHac.Tests.Kvdb
             Assert.Success(PopulateKvStore(kvStore, out _, count));
 
             TTest keyToDelete = entryToDelete;
-            Assert.Success(kvStore.Delete(ref keyToDelete));
+            Assert.Success(kvStore.Delete(in keyToDelete));
 
             FlatMapKeyValueStore<TTest>.Iterator iterator = kvStore.GetBeginIterator();
 
@@ -414,7 +414,7 @@ namespace LibHac.Tests.Kvdb
             Assert.Success(PopulateKvStore(kvStore, out _, count));
 
             TTest startingKey = startEntry;
-            FlatMapKeyValueStore<TTest>.Iterator iterator = kvStore.GetLowerBoundIterator(ref startingKey);
+            FlatMapKeyValueStore<TTest>.Iterator iterator = kvStore.GetLowerBoundIterator(in startingKey);
 
             Assert.False(iterator.IsEnd());
             Assert.Equal(startingKey, iterator.Get().Key);
@@ -436,12 +436,12 @@ namespace LibHac.Tests.Kvdb
             for (int i = 0; i < count; i++)
             {
                 TTest key = i * 2;
-                Assert.Success(kvStore.Set(ref key, values[i]));
+                Assert.Success(kvStore.Set(in key, values[i]));
             }
 
             TTest startingKey = startIndex;
             TTest nextLargestKey = startIndex + 1;
-            FlatMapKeyValueStore<TTest>.Iterator iterator = kvStore.GetLowerBoundIterator(ref startingKey);
+            FlatMapKeyValueStore<TTest>.Iterator iterator = kvStore.GetLowerBoundIterator(in startingKey);
 
             Assert.False(iterator.IsEnd());
             Assert.Equal(nextLargestKey, iterator.Get().Key);
@@ -457,7 +457,7 @@ namespace LibHac.Tests.Kvdb
             Assert.Success(PopulateKvStore(kvStore, out _, count));
 
             TTest key = startIndex;
-            FlatMapKeyValueStore<TTest>.Iterator iterator = kvStore.GetLowerBoundIterator(ref key);
+            FlatMapKeyValueStore<TTest>.Iterator iterator = kvStore.GetLowerBoundIterator(in key);
 
             Assert.True(iterator.IsEnd());
         }
@@ -481,9 +481,9 @@ namespace LibHac.Tests.Kvdb
             }
 
             TTest keyToRemove = entryToRemove;
-            Assert.Success(kvStore.Delete(ref keyToRemove));
+            Assert.Success(kvStore.Delete(in keyToRemove));
 
-            kvStore.FixIterator(ref iterator, ref keyToRemove);
+            kvStore.FixIterator(ref iterator, in keyToRemove);
 
             TTest expectedKey = expectedNewPosition;
             Assert.Equal(expectedKey, iterator.Get().Key);
@@ -504,7 +504,7 @@ namespace LibHac.Tests.Kvdb
             for (int i = 0; i < count; i++)
             {
                 TTest key = i * 2;
-                Assert.Success(kvStore.Set(ref key, values[i]));
+                Assert.Success(kvStore.Set(in key, values[i]));
             }
 
             FlatMapKeyValueStore<TTest>.Iterator iterator = kvStore.GetBeginIterator();
@@ -517,9 +517,9 @@ namespace LibHac.Tests.Kvdb
             TTest keyToAdd = entryToAdd;
             var valueToAdd = new byte[10];
 
-            Assert.Success(kvStore.Set(ref keyToAdd, valueToAdd));
+            Assert.Success(kvStore.Set(in keyToAdd, valueToAdd));
 
-            kvStore.FixIterator(ref iterator, ref keyToAdd);
+            kvStore.FixIterator(ref iterator, in keyToAdd);
 
             TTest expectedKey = expectedNewPosition;
             Assert.Equal(expectedKey, iterator.Get().Key);