diff --git a/grep.c b/grep.c
index 35e12e43c0..60228a95a4 100644
--- a/grep.c
+++ b/grep.c
@@ -492,7 +492,8 @@ static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 	p->ignore_case = opt->ignore_case;
 	p->fixed = opt->fixed;
 
-	if (memchr(p->pattern, 0, p->patternlen) && !opt->pcre2)
+	if (!opt->pcre2 &&
+	    memchr(p->pattern, 0, p->patternlen))
 		die(_("given pattern contains NULL byte (via -f <file>). This is only supported with -P under PCRE v2"));
 
 	p->is_fixed = is_fixed(p->pattern, p->patternlen);