diff --git a/media/ffvpx/ffvpxcommon.mozbuild b/media/ffvpx/ffvpxcommon.mozbuild
index 3a83f781d3f3..5c99418bcab5 100644
--- a/media/ffvpx/ffvpxcommon.mozbuild
+++ b/media/ffvpx/ffvpxcommon.mozbuild
@@ -87,3 +87,18 @@ if CONFIG['MOZ_DEBUG']:
 elif not CONFIG['RELEASE_OR_BETA']:
     # Enable fast assertions in opt builds of Nightly and Aurora.
     DEFINES['ASSERT_LEVEL'] = 1
+
+# clang-cl's <intrin.h> doesn't work the same as MSVC's.  For details, see:
+#
+# http://lists.llvm.org/pipermail/cfe-dev/2016-September/050943.html
+#
+# As a temporary workaround while upstream decides how to address this,
+# we enable modules to make <intrin.h> more MSVC-compatible.
+if CONFIG['CLANG_CL']:
+    CFLAGS += [
+        '-Xclang',
+        '-fmodules',
+        '-Xclang',
+        '-fmodules-cache-path=' + TOPOBJDIR + '/media/ffpvx',
+        '-fbuiltin-module-map',
+    ]