diff --git a/bin/nodejs/callback.h b/bin/nodejs/callback.h
index d5749bb58e47ad272893c2a4f89fd176810cefc7..10c1ad1eecb33ebbe9b084ec8f7163170259f44b 100644
--- a/bin/nodejs/callback.h
+++ b/bin/nodejs/callback.h
@@ -128,7 +128,7 @@ getPresistentCb(std::string_view signal)
 inline std::string_view
 toView(const String::Utf8Value& utf8)
 {
-    return {*utf8, utf8.length()};
+    return {*utf8, (size_t)utf8.length()};
 }
 
 inline SWIGV8_ARRAY