diff --git a/compiler/wasm32/aasmcpu.pas b/compiler/wasm32/aasmcpu.pas
index d3ba39895d..ebd84ebaf5 100644
--- a/compiler/wasm32/aasmcpu.pas
+++ b/compiler/wasm32/aasmcpu.pas
@@ -479,6 +479,7 @@ uses
 
     function TWasmValidationStacks.PopVal(expect: TWasmBasicType): TWasmBasicType;
       begin
+        Result:=wbt_Unknown;
         Result:=PopVal;
         if (Result<>expect) and (Result<>wbt_Unknown) and (expect<>wbt_Unknown) then
           internalerror(2024013105);