diff --git a/simgear/math/simd.hxx b/simgear/math/simd.hxx
index 35508b7b..81782efa 100644
--- a/simgear/math/simd.hxx
+++ b/simgear/math/simd.hxx
@@ -504,7 +504,7 @@ inline simd4_t<float,N>abs(simd4_t<float,N> v) {
 # endif
 
 
-# ifdef __AVX__
+# ifdef __AVX_unsupported__
 #  include <pmmintrin.h>
 #  include <immintrin.h>
 //#  include <avxintrin-emu.h>
diff --git a/simgear/math/simd4x4.hxx b/simgear/math/simd4x4.hxx
index f27a4008..a199d5bb 100644
--- a/simgear/math/simd4x4.hxx
+++ b/simgear/math/simd4x4.hxx
@@ -514,7 +514,7 @@ inline simd4_t<float,3> transform<float>(const simd4x4_t<float,4>& m, const simd
 # endif
 
 
-# ifdef __AVX__
+# ifdef __AVX_unsupported__
 #  include <pmmintrin.h>
 #  include <immintrin.h>
 //#  include <avxintrin-emu.h>