diff --git a/fpdfsdk/cpdfsdk_formfillenvironment.cpp b/fpdfsdk/cpdfsdk_formfillenvironment.cpp
index 4f46db4..7bf6162 100644
--- a/fpdfsdk/cpdfsdk_formfillenvironment.cpp
+++ b/fpdfsdk/cpdfsdk_formfillenvironment.cpp
@@ -39,7 +39,9 @@
 CPDFSDK_FormFillEnvironment::CPDFSDK_FormFillEnvironment(
     CPDF_Document* pDoc,
     FPDF_FORMFILLINFO* pFFinfo)
-    : m_pInfo(pFFinfo), m_pCPDFDoc(pDoc) {}
+    : m_pInfo(pFFinfo), m_pCPDFDoc(pDoc) {
+  ASSERT(m_pCPDFDoc);
+}
 
 CPDFSDK_FormFillEnvironment::~CPDFSDK_FormFillEnvironment() {
   m_bBeingDestroyed = true;
@@ -590,9 +592,6 @@
 }
 
 bool CPDFSDK_FormFillEnvironment::ProcOpenAction() {
-  if (!m_pCPDFDoc)
-    return false;
-
   CPDF_Dictionary* pRoot = m_pCPDFDoc->GetRoot();
   if (!pRoot)
     return false;
diff --git a/fpdfsdk/cpdfsdk_pageview.cpp b/fpdfsdk/cpdfsdk_pageview.cpp
index 3e58929..2a5f179 100644
--- a/fpdfsdk/cpdfsdk_pageview.cpp
+++ b/fpdfsdk/cpdfsdk_pageview.cpp
@@ -571,5 +571,5 @@
 int CPDFSDK_PageView::GetPageIndexForStaticPDF() const {
   const CPDF_Dictionary* pDict = GetPDFPage()->GetDict();
   CPDF_Document* pDoc = m_pFormFillEnv->GetPDFDocument();
-  return pDoc ? pDoc->GetPageIndex(pDict->GetObjNum()) : -1;
+  return pDoc->GetPageIndex(pDict->GetObjNum());
 }
diff --git a/fxjs/cjs_document.cpp b/fxjs/cjs_document.cpp
index d71126d..c7965f0 100644
--- a/fxjs/cjs_document.cpp
+++ b/fxjs/cjs_document.cpp
@@ -823,14 +823,14 @@
 }
 
 CJS_Result CJS_Document::get_title(CJS_Runtime* pRuntime) {
-  if (!m_pFormFillEnv || !m_pFormFillEnv->GetPDFDocument())
+  if (!m_pFormFillEnv)
     return CJS_Result::Failure(JSMessage::kBadObjectError);
   return getPropertyInternal(pRuntime, "Title");
 }
 
 CJS_Result CJS_Document::set_title(CJS_Runtime* pRuntime,
                                    v8::Local<v8::Value> vp) {
-  if (!m_pFormFillEnv || !m_pFormFillEnv->GetPDFDocument())
+  if (!m_pFormFillEnv)
     return CJS_Result::Failure(JSMessage::kBadObjectError);
   return setPropertyInternal(pRuntime, vp, "Title");
 }
@@ -1230,9 +1230,6 @@
   bool bStrip = params.size() > 2 ? pRuntime->ToBoolean(params[2]) : true;
 
   CPDF_Document* pDocument = m_pFormFillEnv->GetPDFDocument();
-  if (!pDocument)
-    return CJS_Result::Failure(JSMessage::kBadObjectError);
-
   if (nPageNo < 0 || nPageNo >= pDocument->GetPageCount())
     return CJS_Result::Failure(JSMessage::kValueError);
 
@@ -1371,9 +1368,6 @@
     return CJS_Result::Failure(JSMessage::kBadObjectError);
 
   CPDF_Document* pDocument = m_pFormFillEnv->GetPDFDocument();
-  if (!pDocument)
-    return CJS_Result::Failure(JSMessage::kBadObjectError);
-
   CPDF_NameTree nameTree(pDocument, "Dests");
   CPDF_Array* destArray =
       nameTree.LookupNamedDest(pDocument, pRuntime->ToWideString(params[0]));