diff --git a/config/config.mk b/config/config.mk
index be861dc7470a..b2ab934c8c9a 100644
--- a/config/config.mk
+++ b/config/config.mk
@@ -888,6 +888,9 @@ export NONASCII
 ifdef MOZ_GTK2_CFLAGS
 MOZ_GTK2_CFLAGS := -I$(topsrcdir)/widget/gtk/compat $(MOZ_GTK2_CFLAGS)
 endif
+ifdef MOZ_GTK3_CFLAGS
+MOZ_GTK3_CFLAGS := -I$(topsrcdir)/widget/gtk/compat-gtk3 $(MOZ_GTK3_CFLAGS)
+endif
 
 DEFINES += -DNO_NSPR_10_SUPPORT
 
diff --git a/widget/gtk/compat/gtk/gtkenums.h b/widget/gtk/compat-gtk3/gtk/gtkenums.h
similarity index 100%
rename from widget/gtk/compat/gtk/gtkenums.h
rename to widget/gtk/compat-gtk3/gtk/gtkenums.h