--- a/media/libvpx/moz.build
+++ b/media/libvpx/moz.build
@@ -100,16 +100,24 @@ if CONFIG['CLANG_CL'] or not CONFIG['_MS
                 SOURCES[f].flags += ['-mssse3']
             if 'sse4.c' in f:
                 SOURCES[f].flags += ['-msse4.1']
             if 'avx.c' in f:
                 SOURCES[f].flags += ['-mavx']
             if 'avx2.c' in f:
                 SOURCES[f].flags += ['-mavx2']
 
+if CONFIG['_MSC_VER'] and not CONFIG['CLANG_CL']:
+    for f in SOURCES:
+        if f.endswith('.c'):
+            if 'avx.c' in f:
+                SOURCES[f].flags += ['-arch:AVX']
+            if 'avx2.c' in f:
+                SOURCES[f].flags += ['-arch:AVX2']
+
 # Suppress warnings in third-party code.
 if CONFIG['GNU_CC'] or CONFIG['CLANG_CL']:
     CFLAGS += [
         '-Wno-sign-compare',
         '-Wno-unused-function', # so many of these warnings; just ignore them
     ]
 if CONFIG['CLANG_CXX'] or CONFIG['CLANG_CL']:
     CFLAGS += [