diff --git a/usr.bin/diff/pr.c b/usr.bin/diff/pr.c
index eaf6e37f9f4..ce8620e1432 100644
--- a/usr.bin/diff/pr.c
+++ b/usr.bin/diff/pr.c
@@ -58,7 +58,8 @@ start_pr(char *file1, char *file2)
 	signal(SIGPIPE, SIG_IGN);
 	fflush(stdout);
 	rewind(stdout);
-	pipe(pfd);
+	if (pipe(pfd) == -1)
+		err(2, "pipe");
 	switch ((pid = pdfork(&pr_pd, PD_CLOEXEC))) {
 	case -1:
 		status |= 2;