diff --git a/src/runtime/c/pgf/data.h b/src/runtime/c/pgf/data.h
index d30fd7a8b..d2f21081a 100644
--- a/src/runtime/c/pgf/data.h
+++ b/src/runtime/c/pgf/data.h
@@ -135,7 +135,7 @@ typedef object PgfSymbol;
 
 struct PGF_INTERNAL_DECL PgfSymbolIdx {
     size_t d;
-    ref<PgfConcrLIndex> r;
+    PgfConcrLIndex r;
 };
 
 struct PGF_INTERNAL_DECL PgfSymbolCat : PgfSymbolIdx {