diff --git a/libasn1compiler/asn1c_C.c b/libasn1compiler/asn1c_C.c
index 5615328..d380876 100644
--- a/libasn1compiler/asn1c_C.c
+++ b/libasn1compiler/asn1c_C.c
@@ -1911,7 +1911,7 @@
 
 		out_name_chain(&tmparg, 0);
 
-		OUT("_");	/* a separator between id components */
+		OUT("__");	/* a separator between id components */
 
 		/* Fall through */
 	}