diff --git a/gfx/thebes/GLContext.cpp b/gfx/thebes/GLContext.cpp
index 842c82a0cd3..e648ce587af 100644
--- a/gfx/thebes/GLContext.cpp
+++ b/gfx/thebes/GLContext.cpp
@@ -53,6 +53,8 @@
 
 #include "gfxCrashReporterUtils.h"
 
+#include "mozilla/Util.h" // for DebugOnly
+
 namespace mozilla {
 namespace gl {
 
@@ -1777,7 +1779,7 @@ GLContext::SetBlitFramebufferForDestTexture(GLuint aTexture)
                           0);
 
     if (aTexture) {
-        GLenum status = fCheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER);
+        DebugOnly<GLenum> status = fCheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER);
 
         // Note: if you are hitting this assertion, it is likely that
         // your texture is not texture complete -- that is, you
diff --git a/gfx/thebes/GLContextProviderEGL.cpp b/gfx/thebes/GLContextProviderEGL.cpp
index b70ba3f6cab..5445ff95eb0 100644
--- a/gfx/thebes/GLContextProviderEGL.cpp
+++ b/gfx/thebes/GLContextProviderEGL.cpp
@@ -1767,7 +1767,6 @@ GetVendor()
 already_AddRefed<GLContext>
 GLContextProviderEGL::CreateForWindow(nsIWidget *aWidget)
 {
-    EGLContext context;
     EGLConfig config;
 
     if (!sEGLLibrary.EnsureInitialized()) {
@@ -2164,14 +2163,13 @@ ContentTypeToGLFormat(gfxASurface::gfxContentType aCType)
 already_AddRefed<GLContext>
 GLContextProviderEGL::CreateForNativePixmapSurface(gfxASurface* aSurface)
 {
-    EGLSurface surface = nsnull;
-    EGLContext context = nsnull;
-    EGLConfig config = nsnull;
-
     if (!sEGLLibrary.EnsureInitialized())
         return nsnull;
 
 #ifdef MOZ_X11
+    EGLSurface surface = nsnull;
+    EGLConfig config = nsnull;
+
     if (aSurface->GetType() != gfxASurface::SurfaceTypeXlib) {
         // Not implemented
         return nsnull;
@@ -2193,9 +2191,6 @@ GLContextProviderEGL::CreateForNativePixmapSurface(gfxASurface* aSurface)
 
     return glContext.forget().get();
 #else
-    (void)surface;
-    (void)context;
-
     // Not implemented
     return nsnull;
 #endif