diff --git a/os/log.c b/os/log.c
index 8aff8f40d..7d91ca0a4 100644
--- a/os/log.c
+++ b/os/log.c
@@ -801,7 +801,7 @@ LogVHdrMessageVerb(MessageType type, int verb, const char *msg_format,
     if (size - len == 1)
         buf[len - 1] = '\n';
 
-    newline = (buf[len - 1] == '\n');
+    newline = (len > 0 && buf[len - 1] == '\n');
     LogSWrite(verb, buf, len, newline);
 }