diff --git a/src/regexp.c b/src/regexp.c
index de066a1..a27c594 100644
--- a/src/regexp.c
+++ b/src/regexp.c
@@ -359,7 +359,9 @@
 
 static char_u e_missingbracket[] = N_("E769: Missing ] after %s[");
 static char_u e_reverse_range[] = N_("E944: Reverse range in character class");
+#ifdef FEAT_MBYTE
 static char_u e_large_class[] = N_("E945: Range too large in character class");
+#endif
 static char_u e_unmatchedpp[] = N_("E53: Unmatched %s%%(");
 static char_u e_unmatchedp[] = N_("E54: Unmatched %s(");
 static char_u e_unmatchedpar[] = N_("E55: Unmatched %s)");