diff --git a/simgear/math/simd4x4.hxx b/simgear/math/simd4x4.hxx
index 8e8bb549..b24a20e8 100644
--- a/simgear/math/simd4x4.hxx
+++ b/simgear/math/simd4x4.hxx
@@ -486,7 +486,7 @@ inline simd4_t<float,3> transform<float>(const simd4x4_t<float,4>& m, const simd
 # endif
 
 
-# ifdef __AVX_unsupported__
+# ifdef __AVX__
 #  include <immintrin.h>
 
 template<>