diff --git a/protocol.c b/protocol.c
index 1206b58c..6f18efad 100644
--- a/protocol.c
+++ b/protocol.c
@@ -665,7 +665,8 @@ enet_protocol_handle_send_unreliable_fragment (ENetHost * host, ENetPeer * peer,
 
     fragmentLength = ENET_NET_TO_HOST_16 (command -> sendFragment.dataLength);
     * currentData += fragmentLength;
-    if (fragmentLength > host -> maximumPacketSize ||
+    if (fragmentLength <= 0 ||
+        fragmentLength > host -> maximumPacketSize ||
         * currentData < host -> receivedData ||
         * currentData > & host -> receivedData [host -> receivedDataLength])
       return -1;
@@ -695,6 +696,7 @@ enet_protocol_handle_send_unreliable_fragment (ENetHost * host, ENetPeer * peer,
     if (fragmentCount > ENET_PROTOCOL_MAXIMUM_FRAGMENT_COUNT ||
         fragmentNumber >= fragmentCount ||
         totalLength > host -> maximumPacketSize ||
+        totalLength < fragmentCount ||
         fragmentOffset >= totalLength ||
         fragmentLength > totalLength - fragmentOffset)
       return -1;