diff --git a/src/shader_recompiler/backend/glasm/emit_glasm_instructions.h b/src/shader_recompiler/backend/glasm/emit_glasm_instructions.h
index 7893f1c2a..8a707d924 100644
--- a/src/shader_recompiler/backend/glasm/emit_glasm_instructions.h
+++ b/src/shader_recompiler/backend/glasm/emit_glasm_instructions.h
@@ -179,7 +179,8 @@ void EmitCompositeExtractF64x4(EmitContext& ctx);
 void EmitCompositeInsertF64x2(EmitContext& ctx, Register composite, Register object, u32 index);
 void EmitCompositeInsertF64x3(EmitContext& ctx, Register composite, Register object, u32 index);
 void EmitCompositeInsertF64x4(EmitContext& ctx, Register composite, Register object, u32 index);
-void EmitSelectU1(EmitContext& ctx, ScalarS32 cond, ScalarS32 true_value, ScalarS32 false_value);
+void EmitSelectU1(EmitContext& ctx, IR::Inst& inst, ScalarS32 cond, ScalarS32 true_value,
+                  ScalarS32 false_value);
 void EmitSelectU8(EmitContext& ctx, ScalarS32 cond, ScalarS32 true_value, ScalarS32 false_value);
 void EmitSelectU16(EmitContext& ctx, ScalarS32 cond, ScalarS32 true_value, ScalarS32 false_value);
 void EmitSelectU32(EmitContext& ctx, IR::Inst& inst, ScalarS32 cond, ScalarS32 true_value,
diff --git a/src/shader_recompiler/backend/glasm/emit_glasm_select.cpp b/src/shader_recompiler/backend/glasm/emit_glasm_select.cpp
index b9e5cbbbe..68fff613c 100644
--- a/src/shader_recompiler/backend/glasm/emit_glasm_select.cpp
+++ b/src/shader_recompiler/backend/glasm/emit_glasm_select.cpp
@@ -9,9 +9,9 @@
 
 namespace Shader::Backend::GLASM {
 
-void EmitSelectU1([[maybe_unused]] EmitContext& ctx, [[maybe_unused]] ScalarS32 cond,
-                  [[maybe_unused]] ScalarS32 true_value, [[maybe_unused]] ScalarS32 false_value) {
-    throw NotImplementedException("GLASM instruction");
+void EmitSelectU1(EmitContext& ctx, IR::Inst& inst, ScalarS32 cond, ScalarS32 true_value,
+                  ScalarS32 false_value) {
+    ctx.Add("CMP.S {},{},{},{};", inst, cond, true_value, false_value);
 }
 
 void EmitSelectU8([[maybe_unused]] EmitContext& ctx, [[maybe_unused]] ScalarS32 cond,