diff --git a/core/fpdfapi/page/cpdf_allstates.cpp b/core/fpdfapi/page/cpdf_allstates.cpp
index 280e512..facd2e7 100644
--- a/core/fpdfapi/page/cpdf_allstates.cpp
+++ b/core/fpdfapi/page/cpdf_allstates.cpp
@@ -71,7 +71,7 @@
         if (!pDash)
           break;
 
-        CPDF_Array* pArray = pDash->GetArrayAt(0);
+        const CPDF_Array* pArray = pDash->GetArrayAt(0);
         if (!pArray)
           break;
 
diff --git a/core/fpdfapi/page/cpdf_occontext.cpp b/core/fpdfapi/page/cpdf_occontext.cpp
index 1318ad8..afeda6a 100644
--- a/core/fpdfapi/page/cpdf_occontext.cpp
+++ b/core/fpdfapi/page/cpdf_occontext.cpp
@@ -34,27 +34,28 @@
   return bsIntent == "All" || bsIntent == csElement;
 }
 
-CPDF_Dictionary* GetConfig(CPDF_Document* pDoc,
-                           const CPDF_Dictionary* pOCGDict) {
+const CPDF_Dictionary* GetConfig(CPDF_Document* pDoc,
+                                 const CPDF_Dictionary* pOCGDict) {
   DCHECK(pOCGDict);
-  CPDF_Dictionary* pOCProperties = pDoc->GetRoot()->GetDictFor("OCProperties");
+  const CPDF_Dictionary* pOCProperties =
+      pDoc->GetRoot()->GetDictFor("OCProperties");
   if (!pOCProperties)
     return nullptr;
 
-  CPDF_Array* pOCGs = pOCProperties->GetArrayFor("OCGs");
+  const CPDF_Array* pOCGs = pOCProperties->GetArrayFor("OCGs");
   if (!pOCGs)
     return nullptr;
 
   if (!pOCGs->Contains(pOCGDict))
     return nullptr;
 
-  CPDF_Dictionary* pConfig = pOCProperties->GetDictFor("D");
-  CPDF_Array* pConfigs = pOCProperties->GetArrayFor("Configs");
+  const CPDF_Dictionary* pConfig = pOCProperties->GetDictFor("D");
+  const CPDF_Array* pConfigs = pOCProperties->GetArrayFor("Configs");
   if (!pConfigs)
     return pConfig;
 
   for (size_t i = 0; i < pConfigs->size(); i++) {
-    CPDF_Dictionary* pFind = pConfigs->GetDictAt(i);
+    const CPDF_Dictionary* pFind = pConfigs->GetDictAt(i);
     if (pFind && HasIntent(pFind, "View", ""))
       return pFind;
   }
@@ -92,12 +93,12 @@
 bool CPDF_OCContext::LoadOCGStateFromConfig(
     const ByteString& csConfig,
     const CPDF_Dictionary* pOCGDict) const {
-  CPDF_Dictionary* pConfig = GetConfig(m_pDocument.Get(), pOCGDict);
+  const CPDF_Dictionary* pConfig = GetConfig(m_pDocument.Get(), pOCGDict);
   if (!pConfig)
     return true;
 
   bool bState = pConfig->GetStringFor("BaseState", "ON") != "OFF";
-  CPDF_Array* pArray = pConfig->GetArrayFor("ON");
+  const CPDF_Array* pArray = pConfig->GetArrayFor("ON");
   if (pArray && pArray->Contains(pOCGDict))
     bState = true;
 
@@ -111,21 +112,21 @@
 
   ByteString csFind = csConfig + "State";
   for (size_t i = 0; i < pArray->size(); i++) {
-    CPDF_Dictionary* pUsage = pArray->GetDictAt(i);
+    const CPDF_Dictionary* pUsage = pArray->GetDictAt(i);
     if (!pUsage)
       continue;
 
     if (pUsage->GetStringFor("Event", "View") != csConfig)
       continue;
 
-    CPDF_Array* pOCGs = pUsage->GetArrayFor("OCGs");
+    const CPDF_Array* pOCGs = pUsage->GetArrayFor("OCGs");
     if (!pOCGs)
       continue;
 
     if (!pOCGs->Contains(pOCGDict))
       continue;
 
-    CPDF_Dictionary* pState = pUsage->GetDictFor(csConfig);
+    const CPDF_Dictionary* pState = pUsage->GetDictFor(csConfig);
     if (!pState)
       continue;
 
diff --git a/core/fpdfdoc/cpdf_annot.cpp b/core/fpdfdoc/cpdf_annot.cpp
index ab0cc4e..49bcf2e 100644
--- a/core/fpdfdoc/cpdf_annot.cpp
+++ b/core/fpdfdoc/cpdf_annot.cpp
@@ -445,7 +445,7 @@
   CPDF_Dictionary* pBS = m_pAnnotDict->GetDictFor("BS");
   char style_char;
   float width;
-  CPDF_Array* pDashArray = nullptr;
+  const CPDF_Array* pDashArray = nullptr;
   if (!pBS) {
     CPDF_Array* pBorderArray =
         m_pAnnotDict->GetArrayFor(pdfium::annotation::kBorder);
@@ -460,7 +460,7 @@
         size_t nLen = pDashArray->size();
         size_t i = 0;
         for (; i < nLen; ++i) {
-          CPDF_Object* pObj = pDashArray->GetDirectObjectAt(i);
+          const CPDF_Object* pObj = pDashArray->GetDirectObjectAt(i);
           if (pObj && pObj->GetInteger()) {
             break;
           }
diff --git a/core/fpdfdoc/cpdf_generateap.cpp b/core/fpdfdoc/cpdf_generateap.cpp
index 38d2439..3a26bd5 100644
--- a/core/fpdfdoc/cpdf_generateap.cpp
+++ b/core/fpdfdoc/cpdf_generateap.cpp
@@ -664,7 +664,7 @@
   pAnnotDict->SetRectFor(pdfium::annotation::kRect, rect);
 
   for (size_t i = 0; i < pInkList->size(); i++) {
-    CPDF_Array* pInkCoordList = pInkList->GetArrayAt(i);
+    const CPDF_Array* pInkCoordList = pInkList->GetArrayAt(i);
     if (!pInkCoordList || pInkCoordList->size() < 2)
       continue;
 
diff --git a/core/fpdfdoc/cpdf_interactiveform.cpp b/core/fpdfdoc/cpdf_interactiveform.cpp
index 61fa8fe..b7bb38e 100644
--- a/core/fpdfdoc/cpdf_interactiveform.cpp
+++ b/core/fpdfdoc/cpdf_interactiveform.cpp
@@ -759,7 +759,7 @@
     return;
   }
 
-  CPDF_Dictionary* pFirstKid = pKids->GetDictAt(0);
+  const CPDF_Dictionary* pFirstKid = pKids->GetDictAt(0);
   if (!pFirstKid)
     return;
 
diff --git a/core/fpdfdoc/cpdf_nametree.cpp b/core/fpdfdoc/cpdf_nametree.cpp
index 76355f9..e818e1c 100644
--- a/core/fpdfdoc/cpdf_nametree.cpp
+++ b/core/fpdfdoc/cpdf_nametree.cpp
@@ -151,7 +151,7 @@
     WideString csNewLeft = csRight;
     WideString csNewRight = csLeft;
     for (size_t j = 0; j < pKids->size(); ++j) {
-      CPDF_Array* pKidLimits = pKids->GetDictAt(j)->GetArrayFor("Limits");
+      const CPDF_Array* pKidLimits = pKids->GetDictAt(j)->GetArrayFor("Limits");
       DCHECK(pKidLimits);
       if (pKidLimits->GetUnicodeTextAt(0).Compare(csNewLeft) < 0)
         csNewLeft = pKidLimits->GetUnicodeTextAt(0);
diff --git a/fpdfsdk/cpdfsdk_interactiveform.cpp b/fpdfsdk/cpdfsdk_interactiveform.cpp
index 602fe39..25dd6b9 100644
--- a/fpdfsdk/cpdfsdk_interactiveform.cpp
+++ b/fpdfsdk/cpdfsdk_interactiveform.cpp
@@ -85,7 +85,7 @@
 
   fxcrt::ostringstream fdfEncodedData;
   for (uint32_t i = 0; i < pFields->size(); i++) {
-    CPDF_Dictionary* pField = pFields->GetDictAt(i);
+    const CPDF_Dictionary* pField = pFields->GetDictAt(i);
     if (!pField)
       continue;
     WideString name = pField->GetUnicodeTextFor("T");