diff --git a/src/naveditor/Editor_TileMesh.cpp b/src/naveditor/Editor_TileMesh.cpp
index 1df4a817..dcd6b812 100644
--- a/src/naveditor/Editor_TileMesh.cpp
+++ b/src/naveditor/Editor_TileMesh.cpp
@@ -811,7 +811,7 @@ void Editor_TileMesh::buildAllTiles()
 	}
 
 	// Reserve the first poly groups
-	// 0 = technically usable for normal poly groups, but for possible internal usage we reserve it for now.
+	// 0 = DT_NULL_POLY_GROUP.
 	// 1 = DT_STRAY_POLY_GROUP.
 	dtDisjointSet data(DT_FIRST_USABLE_POLY_GROUP);
 
diff --git a/src/thirdparty/recast/Detour/Include/DetourNavMesh.h b/src/thirdparty/recast/Detour/Include/DetourNavMesh.h
index 0eaeeb8b..40eef111 100644
--- a/src/thirdparty/recast/Detour/Include/DetourNavMesh.h
+++ b/src/thirdparty/recast/Detour/Include/DetourNavMesh.h
@@ -63,6 +63,9 @@ typedef unsigned int dtTileRef;
 /// @ingroup detour
 static const int DT_VERTS_PER_POLYGON = 6;
 
+/// A value that indicates that this poly hasn't been assigned to a group yet.
+static const unsigned short DT_NULL_POLY_GROUP = 0;
+
 /// A poly group that holds all unconnected stray polys (not linked to anything).
 /// These are considered 'trash' by the game engine; see [r5apex_ds + CA88B2]. 
 /// For reference, Titanfall 2 single player NavMeshes also marked everything unconnected as '1'.
diff --git a/src/thirdparty/recast/Detour/Source/DetourNavMeshBuilder.cpp b/src/thirdparty/recast/Detour/Source/DetourNavMeshBuilder.cpp
index 5e0833e2..fabee81a 100644
--- a/src/thirdparty/recast/Detour/Source/DetourNavMeshBuilder.cpp
+++ b/src/thirdparty/recast/Detour/Source/DetourNavMeshBuilder.cpp
@@ -294,7 +294,7 @@ bool dtCreateDisjointPolyGroups(dtNavMesh* nav, dtDisjointSet& disjoint)
 		for (int j = 0; j < pcount; j++)
 		{
 			dtPoly& poly = tile->polys[j];
-			poly.groupId = (unsigned short)-1;
+			poly.groupId = DT_NULL_POLY_GROUP;
 
 			// NOTE: these fields are unknown and need to be reversed.
 			// It is possible these are used internally only.
@@ -332,7 +332,7 @@ bool dtCreateDisjointPolyGroups(dtNavMesh* nav, dtDisjointSet& disjoint)
 					const dtPoly* p;
 					nav->getTileAndPolyByRefUnsafe(l.ref, &t, &p);
 
-					if (p->groupId != (unsigned short)-1)
+					if (p->groupId != DT_NULL_POLY_GROUP)
 						nlabels.insert(p->groupId);
 
 					plink = l.next;