diff --git a/lib/delphi/src/Thrift.Utils.pas b/lib/delphi/src/Thrift.Utils.pas
index 05fb964..15ea36f 100644
--- a/lib/delphi/src/Thrift.Utils.pas
+++ b/lib/delphi/src/Thrift.Utils.pas
@@ -141,6 +141,7 @@
 
   else
     ASSERT( FALSE);
+    result := 0;  // because invalid call
   end;
 end;