diff --git a/plugins/docsis/packet-docsis.c b/plugins/docsis/packet-docsis.c
index 6f4b2a686e..30af37ae83 100644
--- a/plugins/docsis/packet-docsis.c
+++ b/plugins/docsis/packet-docsis.c
@@ -825,6 +825,10 @@ dissect_docsis (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* da
           concatpos = 0;
           break;
         }
+        default:
+            /* Unknown parameter, stop dissection */
+          concatlen = 0;
+          break;
       } /* switch fcparm */
       break;
     }