diff --git a/lib/swift/Sources/TProtocol.swift b/lib/swift/Sources/TProtocol.swift
index a4e4a20..b111e71 100644
--- a/lib/swift/Sources/TProtocol.swift
+++ b/lib/swift/Sources/TProtocol.swift
@@ -175,8 +175,9 @@
         try skip(type: elemType)
       }
       try readListEnd()
+      
     default:
-      return
+      throw TProtocolError(error: .invalidData, message: "Invalid data")
     }
   }
 }