diff --git a/builtin-grep.c b/builtin-grep.c
index 9e7e766a49..89489ddcf8 100644
--- a/builtin-grep.c
+++ b/builtin-grep.c
@@ -825,6 +825,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 		}
 	}
 
+	if (opt.color && !opt.color_external)
+		builtin_grep = 1;
 	if (!opt.pattern_list)
 		die("no pattern given.");
 	if ((opt.regflags != REG_NEWLINE) && opt.fixed)