diff --git a/grep.h b/grep.h
index 3112d1c2a3..89a2ce5113 100644
--- a/grep.h
+++ b/grep.h
@@ -164,7 +164,7 @@ struct grep_opt {
 	int funcname;
 	int funcbody;
 	int extended_regexp_option;
-	int pattern_type_option;
+	enum grep_pattern_type pattern_type_option;
 	int ignore_locale;
 	char colors[NR_GREP_COLORS][COLOR_MAXLEN];
 	unsigned pre_context;