diff --git a/lib/php/src/protocol/TProtocol.php b/lib/php/src/protocol/TProtocol.php
index ac1facd..239648e 100644
--- a/lib/php/src/protocol/TProtocol.php
+++ b/lib/php/src/protocol/TProtocol.php
@@ -262,7 +262,8 @@
         return $result;
       }
     default:
-      return 0;
+      throw new TProtocolException('Unknown field type: '.$type,
+                                   TProtocolException::INVALID_DATA);
     }
   }
 
@@ -356,7 +357,8 @@
         return $result;
       }
     default:
-      return 0;
+      throw new TProtocolException('Unknown field type: '.$type,
+                                   TProtocolException::INVALID_DATA);
     }
   }
 }