diff --git a/idlib/math/Simd_3DNow.cpp b/idlib/math/Simd_3DNow.cpp
index fc877f9..194a491 100644
--- a/idlib/math/Simd_3DNow.cpp
+++ b/idlib/math/Simd_3DNow.cpp
@@ -290,4 +290,4 @@ $memcpy_final:
 	}
 }
 
-#endif /* _WIN32 */
+#endif /* _MSC_VER */
diff --git a/idlib/math/Simd_Generic.cpp b/idlib/math/Simd_Generic.cpp
index f4d0fd5..c20f6a4 100644
--- a/idlib/math/Simd_Generic.cpp
+++ b/idlib/math/Simd_Generic.cpp
@@ -49,7 +49,7 @@ If you have questions concerning this license or the applicable additional terms
 
 #ifdef _DEBUG
 #define NODEFAULT	default: assert( 0 )
-#elif _WIN32
+#elif _MSC_VER
 #define NODEFAULT	default: __assume( 0 )
 #else
 #define NODEFAULT
diff --git a/idlib/math/Simd_SSE2.cpp b/idlib/math/Simd_SSE2.cpp
index 986f8d8..1a4b4a9 100644
--- a/idlib/math/Simd_SSE2.cpp
+++ b/idlib/math/Simd_SSE2.cpp
@@ -872,4 +872,4 @@ void VPCALL idSIMD_SSE2::MixedSoundToSamples( short *samples, const float *mixBu
 	}
 }
 
-#endif /* _WIN32 */
+#endif /* _MSC_VER */
diff --git a/idlib/math/Simd_SSE3.cpp b/idlib/math/Simd_SSE3.cpp
index 4ecd799..8ea6d5d 100644
--- a/idlib/math/Simd_SSE3.cpp
+++ b/idlib/math/Simd_SSE3.cpp
@@ -362,4 +362,4 @@ void VPCALL idSIMD_SSE3::TransformVerts( idDrawVert *verts, const int numVerts,
 #endif
 }
 
-#endif /* _WIN32 */
+#endif /* _MSC_VER */