diff --git a/mkspecs/features/simd.prf b/mkspecs/features/simd.prf
index ad8c545819..a8ce097b64 100644
--- a/mkspecs/features/simd.prf
+++ b/mkspecs/features/simd.prf
@@ -289,7 +289,7 @@ QT_CPU_FEATURES = $$eval(QT_CPU_FEATURES.$$QT_ARCH)
     avx2 {
         HEADERS += $$AVX2_HEADERS
 
-        avx2_compiler.commands = $$QMAKE_CXX -c $(CXXFLAGS) -D_M_AVX2
+        avx2_compiler.commands = $$QMAKE_CXX -c $(CXXFLAGS)
         !contains(QT_CPU_FEATURES, avx):avx2_compiler.commands += $$QMAKE_CFLAGS_AVX2
         avx2_compiler.commands += $(INCPATH) ${QMAKE_FILE_IN} -Fo${QMAKE_FILE_OUT}
         avx2_compiler.dependency_type = TYPE_C
diff --git a/src/corelib/tools/qsimd_p.h b/src/corelib/tools/qsimd_p.h
index dd720f88da..d293532f1d 100644
--- a/src/corelib/tools/qsimd_p.h
+++ b/src/corelib/tools/qsimd_p.h
@@ -56,7 +56,8 @@
  *
  * We will try to include all headers possible under this configuration.
  *
- * MSVC does not define __SSE2__ & family, so we will define them.
+ * MSVC does not define __SSE2__ & family, so we will define them. MSVC 2013 &
+ * up do define __AVX__ if the -arch:AVX option is passed on the command-line.
  *
  * Supported XXX are:
  *   Flag  | Arch |  GCC  | Intel CC |  MSVC  |
@@ -118,23 +119,18 @@
 // immintrin.h is the ultimate header, we don't need anything else after this
 #include <immintrin.h>
 
-#  if defined(Q_CC_MSVC) && defined(_M_AVX)
+#  if defined(Q_CC_MSVC) && (defined(_M_AVX) || defined(__AVX__))
 // MS Visual Studio 2010 has no macro pre-defined to identify the use of /arch:AVX
+// MS Visual Studio 2013 adds it: __AVX__
 // See: http://connect.microsoft.com/VisualStudio/feedback/details/605858/arch-avx-should-define-a-predefined-macro-in-x64-and-set-a-unique-value-for-m-ix86-fp-in-win32
-// When such a macro exists, add it above, replacing _M_AVX as appropriate
 #    define __SSE3__ 1
 #    define __SSSE3__ 1
 // no Intel CPU supports SSE4a, so don't define it
 #    define __SSE4_1__ 1
 #    define __SSE4_2__ 1
-#    define __AVX__ 1
-#    ifdef _M_AVX2
-// replace the macro above with the proper MS macro when it exists
-// All processors with AVX2 will support BMI1 and FMA
-#      define __AVX2__ 1
-#      define __BMI__ 1
-#      define __FMA__ 1
-#   endif
+#    ifndef __AVX__
+#      define __AVX__ 1
+#    endif
 #  endif
 #endif