--- a/gfx/gl/GLContext.h
+++ b/gfx/gl/GLContext.h
@@ -753,18 +753,20 @@ private:
 
             if (err != LOCAL_GL_NO_ERROR &&
                 !mLocalErrorScopeStack.size())
             {
                 printf_stderr("[gl:%p] %s: Generated unexpected %s error."
                               " (0x%04x)\n", this, funcName,
                               GLErrorToString(err), err);
 
-                if (mDebugFlags & DebugFlagAbortOnError)
-                    MOZ_CRASH("MOZ_GL_DEBUG_ABORT_ON_ERROR");
+                if (mDebugFlags & DebugFlagAbortOnError) {
+                    MOZ_CRASH("Unexpected error with MOZ_GL_DEBUG_ABORT_ON_ERROR. (Run"
+                              " with MOZ_GL_DEBUG_ABORT_ON_ERROR=0 to disable)");
+                }
             }
         }
     }
 
     GLContext *TrackingContext()
     {
         GLContext *tip = this;
         while (tip->mSharedContext)