diff --git a/cmake/tools/SetupWebKit.cmake b/cmake/tools/SetupWebKit.cmake
index 85bac91e7b..6e2ce7d677 100644
--- a/cmake/tools/SetupWebKit.cmake
+++ b/cmake/tools/SetupWebKit.cmake
@@ -2,7 +2,7 @@ option(WEBKIT_VERSION "The version of WebKit to use")
 option(WEBKIT_LOCAL "If a local version of WebKit should be used instead of downloading")
 
 if(NOT WEBKIT_VERSION)
-  set(WEBKIT_VERSION 2317e1413969bff5e86d240f9f50aa2120776414)
+  set(WEBKIT_VERSION 863778130931e0081a688f48e8479b8ee61b9507)
 endif()
 
 string(SUBSTRING ${WEBKIT_VERSION} 0 16 WEBKIT_VERSION_PREFIX)
diff --git a/src/bun.js/bindings/Serialization.cpp b/src/bun.js/bindings/Serialization.cpp
index 5385e153db..caaec599f8 100644
--- a/src/bun.js/bindings/Serialization.cpp
+++ b/src/bun.js/bindings/Serialization.cpp
@@ -54,7 +54,9 @@ extern "C" SerializedValueSlice Bun__serializeJSValue(JSGlobalObject* globalObje
 
 extern "C" void Bun__SerializedScriptSlice__free(SerializedScriptValue* value)
 {
-    delete value;
+    // Use deref() instead of delete to properly handle CHECK_REF_COUNTED_LIFECYCLE.
+    // The value was leaked via leakRef() which leaves refcount at 1, so deref() will delete it.
+    value->deref();
 }
 
 extern "C" EncodedJSValue Bun__JSValue__deserialize(JSGlobalObject* globalObject, const uint8_t* bytes, size_t size)