diff --git a/fxjs/xfa/cjx_form.cpp b/fxjs/xfa/cjx_form.cpp
index 0a65286..41f7e45 100644
--- a/fxjs/xfa/cjx_form.cpp
+++ b/fxjs/xfa/cjx_form.cpp
@@ -82,8 +82,8 @@
     const std::vector<v8::Local<v8::Value>>& params) {
   CXFA_EventParam* pEventParam =
       GetDocument()->GetScriptContext()->GetEventParam();
-  if (pEventParam->m_eType == XFA_EVENT_Calculate ||
-      pEventParam->m_eType == XFA_EVENT_InitCalculate) {
+  if (pEventParam && (pEventParam->m_eType == XFA_EVENT_Calculate ||
+                      pEventParam->m_eType == XFA_EVENT_InitCalculate)) {
     return CJS_Result::Success();
   }
   if (params.size() != 1)