diff --git a/lib/libc/gen/err.c b/lib/libc/gen/err.c
--- a/lib/libc/gen/err.c
+++ b/lib/libc/gen/err.c
@@ -119,7 +119,7 @@
 		fprintf(err_file, ": ");
 	}
 	fprintf(err_file, "%s", strerror(code));
-	if (doexterr && extstatus == 0)
+	if (doexterr && extstatus == 0 && exterr[0] != '\0')
 		fprintf(err_file, " (extended error %s)", exterr);
 	fprintf(err_file, "\n");
 }
diff --git a/lib/libc/gen/uexterr_format.c b/lib/libc/gen/uexterr_format.c
--- a/lib/libc/gen/uexterr_format.c
+++ b/lib/libc/gen/uexterr_format.c
@@ -20,7 +20,7 @@
 	if (bufsz > UEXTERROR_MAXLEN)
 		bufsz = UEXTERROR_MAXLEN;
 	if (ue->error == 0) {
-		strlcpy(buf, "No error", bufsz);
+		strlcpy(buf, "", bufsz);
 		return (0);
 	}
 	if (ue->msg[0] == '\0') {