diff --git a/dom/canvas/WebGL2Context.cpp b/dom/canvas/WebGL2Context.cpp
index 7a695c0c8c04..0ecd60e5569e 100644
--- a/dom/canvas/WebGL2Context.cpp
+++ b/dom/canvas/WebGL2Context.cpp
@@ -5,10 +5,10 @@
 
 #include "WebGL2Context.h"
 
+#include "gfxPrefs.h"
 #include "GLContext.h"
 #include "mozilla/dom/WebGL2RenderingContextBinding.h"
 #include "mozilla/ArrayUtils.h"
-#include "mozilla/Preferences.h"
 #include "mozilla/Telemetry.h"
 #include "WebGLBuffer.h"
 #include "WebGLFormats.h"
@@ -37,7 +37,7 @@ WebGL2Context::CreateFormatUsage(gl::GLContext* gl) const
 /*static*/ bool
 WebGL2Context::IsSupported()
 {
-    return Preferences::GetBool("webgl.enable-prototype-webgl2", false);
+    return gfxPrefs::WebGL2Enabled();
 }
 
 /*static*/ WebGL2Context*
diff --git a/gfx/thebes/gfxPrefs.h b/gfx/thebes/gfxPrefs.h
index abd62ac8901f..7bb41fdc8eb9 100644
--- a/gfx/thebes/gfxPrefs.h
+++ b/gfx/thebes/gfxPrefs.h
@@ -428,6 +428,7 @@ private:
 
   DECL_GFX_PREF(Live, "webgl.enable-draft-extensions",         WebGLDraftExtensionsEnabled, bool, false);
   DECL_GFX_PREF(Live, "webgl.enable-privileged-extensions",    WebGLPrivilegedExtensionsEnabled, bool, false);
+  DECL_GFX_PREF(Once, "webgl.enable-prototype-webgl2",         WebGL2Enabled, bool, false);
   DECL_GFX_PREF(Live, "webgl.force-enabled",                   WebGLForceEnabled, bool, false);
   DECL_GFX_PREF(Once, "webgl.force-layers-readback",           WebGLForceLayersReadback, bool, false);
   DECL_GFX_PREF(Live, "webgl.lose-context-on-memory-pressure", WebGLLoseContextOnMemoryPressure, bool, false);