diff -r 66cd5d9893dd -r 882f5f1e5f6f stage4/generate_c/generate_c_typedecl.cc
--- a/stage4/generate_c/generate_c_typedecl.cc	Tue Jun 28 19:03:15 2011 +0200
+++ b/stage4/generate_c/generate_c_typedecl.cc	Wed Jun 29 12:26:00 2011 +0200
@@ -343,7 +343,7 @@
 
     value_type->accept(*basedecl);
   }
-  s4o_incl.print("_");
+  s4o_incl.print("__");
   symbol->value->accept(*basedecl);
   return NULL;
 }