diff --git a/src/node_wasm_web_api.h b/src/node_wasm_web_api.h
index da584be1592cb4..f56b9b3d5aa7f7 100644
--- a/src/node_wasm_web_api.h
+++ b/src/node_wasm_web_api.h
@@ -39,7 +39,7 @@ class WasmStreamingObject final : public BaseObject {
   static void Abort(const v8::FunctionCallbackInfo<v8::Value>& args);
 
   std::shared_ptr<v8::WasmStreaming> streaming_;
-  size_t wasm_size_;
+  size_t wasm_size_ = 0;
 };
 
 // This is a v8::WasmStreamingCallback implementation that must be passed to