diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index 359ce5b..5e4fadd 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -5150,7 +5150,7 @@
 
 	default:
 	    // should not be here :P
-	    siemsg(e_nfa_regexp_invalid_character_class_nr, class);
+	    siemsg(_(e_nfa_regexp_invalid_character_class_nr), class);
 	    return FAIL;
     }
     return FAIL;