--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -2921,17 +2921,6 @@ validate_identifier(const char *identifier, YYLTYPE loc,
       _mesa_glsl_error(&loc, state,
                        "identifier `%s' uses reserved `gl_' prefix",
                        identifier);
-   } else if (strstr(identifier, "__")) {
-      /* From page 14 (page 20 of the PDF) of the GLSL 1.10
-       * spec:
-       *
-       *     "In addition, all identifiers containing two
-       *      consecutive underscores (__) are reserved as
-       *      possible future keywords."
-       */
-      _mesa_glsl_error(&loc, state,
-                       "identifier `%s' uses reserved `__' string",
-                       identifier);
    }
 }