--- a/configure.in
+++ b/configure.in
@@ -5900,16 +5900,20 @@ MOZ_ARG_DISABLE_BOOL(webgl,
     MOZ_WEBGL_DISABLED=1,
     MOZ_WEBGL_DISABLED=)
 
 if test -n "$MOZ_WEBGL_DISABLED"; then
   MOZ_WEBGL=
   MOZ_ANGLE_RENDERER=
 fi
 
+if test -n "$MOZ_WEBGL"; then
+  AC_DEFINE(MOZ_WEBGL)
+fi
+
 if test -n "$MOZ_WEBGL_CONFORMANT"; then
   AC_DEFINE(MOZ_WEBGL_CONFORMANT)
 fi
 
 # Locate a DirectX SDK here so we can use it for both ANGLE and
 # Joystick support.
 if test "$OS_TARGET" = "WINNT" -a -z "$CROSS_COMPILE"; then
   # Get the SDK path from the registry.

--- a/content/html/content/src/Makefile.in
+++ b/content/html/content/src/Makefile.in
@@ -37,12 +37,8 @@ INCLUDES	+= \
 		-I$(srcdir) \
 		-I$(topsrcdir)/xpcom/ds \
 		-I$(topsrcdir)/content/media/ \
 		$(NULL)
 
 DEFINES		+= \
 		-D_IMPL_NS_LAYOUT \
 		$(NULL)
-
-ifdef MOZ_WEBGL
-DEFINES += -DMOZ_WEBGL
-endif

--- a/gfx/gl/Makefile.in
+++ b/gfx/gl/Makefile.in
@@ -13,17 +13,16 @@ LIBRARY_NAME     = gl
 MSVC_ENABLE_PGO := 1
 LIBXUL_LIBRARY   = 1
 EXPORT_LIBRARY   = 1
 FAIL_ON_WARNINGS = 1
 
 
 ifeq ($(MOZ_WIDGET_TOOLKIT),windows)
 ifdef MOZ_WEBGL
-DEFINES += -DMOZ_WEBGL
 DEFINES += -DMOZ_D3DCOMPILER_DLL=$(MOZ_D3DCOMPILER_DLL)
 endif
 endif
 
 # NOTE: Please keep GL_PROVIDER in sync with moz.build until all variables
 # are moved over.
 GL_PROVIDER = Null