diff --git a/lib/libc/gen/err.c b/lib/libc/gen/err.c
index 4193eca77f60..c536767f1a6b 100644
--- a/lib/libc/gen/err.c
+++ b/lib/libc/gen/err.c
@@ -161,6 +161,9 @@ warnc(int code, const char *fmt, ...)
 void
 vwarnc(int code, const char *fmt, va_list ap)
 {
+	static int saved_errno;
+
+	saved_errno = errno;
 	if (err_file == NULL)
 		err_set_file(NULL);
 	fprintf(err_file, "%s: ", _getprogname());
@@ -169,6 +172,7 @@ vwarnc(int code, const char *fmt, va_list ap)
 		fprintf(err_file, ": ");
 	}
 	fprintf(err_file, "%s\n", strerror(code));
+	errno = saved_errno;
 }
 
 void
@@ -183,10 +187,14 @@ warnx(const char *fmt, ...)
 void
 vwarnx(const char *fmt, va_list ap)
 {
+	static int saved_errno;
+
+	saved_errno = errno;
 	if (err_file == NULL)
 		err_set_file(NULL);
 	fprintf(err_file, "%s: ", _getprogname());
 	if (fmt != NULL)
 		vfprintf(err_file, fmt, ap);
 	fprintf(err_file, "\n");
+	errno = saved_errno;
 }