diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index fcca818..919dadc 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -1359,7 +1359,7 @@
 		    rc_did_emsg = TRUE;
 		    return FAIL;
 		}
-		EMSGN("INTERNAL: Unknown character class char: %ld", c);
+		IEMSGN("INTERNAL: Unknown character class char: %ld", c);
 		return FAIL;
 	    }
 #ifdef FEAT_MBYTE
@@ -4925,7 +4925,7 @@
 
 	default:
 	    /* should not be here :P */
-	    EMSGN(_(e_ill_char_class), class);
+	    IEMSGN(_(e_ill_char_class), class);
 	    return FAIL;
     }
     return FAIL;
@@ -6688,7 +6688,7 @@
 
 #ifdef DEBUG
 		if (c < 0)
-		    EMSGN("INTERNAL: Negative state char: %ld", c);
+		    IEMSGN("INTERNAL: Negative state char: %ld", c);
 #endif
 		result = (c == curc);
 
@@ -7216,7 +7216,7 @@
     {
 	/* TODO: only give this error for debugging? */
 	if (post_ptr >= post_end)
-	    EMSGN("Internal error: estimated max number of states insufficient: %ld", post_end - post_start);
+	    IEMSGN("Internal error: estimated max number of states insufficient: %ld", post_end - post_start);
 	goto fail;	    /* Cascaded (syntax?) error */
     }