diff --git a/lib/log.c b/lib/log.c
index 375730f..b24dacd 100644
--- a/lib/log.c
+++ b/lib/log.c
@@ -498,3 +498,11 @@
     }
   return meslist[index].str;
 }
+
+/* Wrapper around strerror to handle case where it returns NULL. */
+const char *
+safe_strerror(int errnum)
+{
+  const char *s = strerror(errnum);
+  return (s != NULL) ? s : "Unknown error";
+}