diff --git a/core/fpdfapi/page/cpdf_contentparser.cpp b/core/fpdfapi/page/cpdf_contentparser.cpp
index 85f1f1a..8308d0b 100644
--- a/core/fpdfapi/page/cpdf_contentparser.cpp
+++ b/core/fpdfapi/page/cpdf_contentparser.cpp
@@ -50,7 +50,7 @@
 }
 
 CPDF_ContentParser::CPDF_ContentParser(CPDF_Form* pForm,
-                                       CPDF_AllStates* pGraphicStates,
+                                       const CPDF_AllStates* pGraphicStates,
                                        const CFX_Matrix* pParentMatrix,
                                        CPDF_Type3Char* pType3Char,
                                        std::set<const uint8_t*>* parsedSet)
diff --git a/core/fpdfapi/page/cpdf_contentparser.h b/core/fpdfapi/page/cpdf_contentparser.h
index 2b8022f..4576638 100644
--- a/core/fpdfapi/page/cpdf_contentparser.h
+++ b/core/fpdfapi/page/cpdf_contentparser.h
@@ -28,7 +28,7 @@
  public:
   explicit CPDF_ContentParser(CPDF_Page* pPage);
   CPDF_ContentParser(CPDF_Form* pForm,
-                     CPDF_AllStates* pGraphicStates,
+                     const CPDF_AllStates* pGraphicStates,
                      const CFX_Matrix* pParentMatrix,
                      CPDF_Type3Char* pType3Char,
                      std::set<const uint8_t*>* parsedSet);
diff --git a/core/fpdfapi/page/cpdf_form.cpp b/core/fpdfapi/page/cpdf_form.cpp
index 16ec824..31b4133 100644
--- a/core/fpdfapi/page/cpdf_form.cpp
+++ b/core/fpdfapi/page/cpdf_form.cpp
@@ -45,7 +45,7 @@
 
 CPDF_Form::~CPDF_Form() = default;
 
-void CPDF_Form::ParseContent(CPDF_AllStates* pGraphicStates,
+void CPDF_Form::ParseContent(const CPDF_AllStates* pGraphicStates,
                              const CFX_Matrix* pParentMatrix,
                              CPDF_Type3Char* pType3Char,
                              std::set<const uint8_t*>* parsedSet) {
diff --git a/core/fpdfapi/page/cpdf_form.h b/core/fpdfapi/page/cpdf_form.h
index 8d98d6d..f00a205 100644
--- a/core/fpdfapi/page/cpdf_form.h
+++ b/core/fpdfapi/page/cpdf_form.h
@@ -35,7 +35,7 @@
             CPDF_Dictionary* pParentResources);
   ~CPDF_Form() override;
 
-  void ParseContent(CPDF_AllStates* pGraphicStates,
+  void ParseContent(const CPDF_AllStates* pGraphicStates,
                     const CFX_Matrix* pParentMatrix,
                     CPDF_Type3Char* pType3Char,
                     std::set<const uint8_t*>* parsedSet);
diff --git a/core/fpdfapi/page/cpdf_streamcontentparser.cpp b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
index 2e53764..adc7c49 100644
--- a/core/fpdfapi/page/cpdf_streamcontentparser.cpp
+++ b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
@@ -254,7 +254,7 @@
     CPDF_PageObjectHolder* pObjHolder,
     CPDF_Dictionary* pResources,
     const CFX_FloatRect& rcBBox,
-    CPDF_AllStates* pStates,
+    const CPDF_AllStates* pStates,
     std::set<const uint8_t*>* parsedSet)
     : m_pDocument(pDocument),
       m_pPageResources(pPageResources),
diff --git a/core/fpdfapi/page/cpdf_streamcontentparser.h b/core/fpdfapi/page/cpdf_streamcontentparser.h
index 8d08dfa..63e344c 100644
--- a/core/fpdfapi/page/cpdf_streamcontentparser.h
+++ b/core/fpdfapi/page/cpdf_streamcontentparser.h
@@ -42,7 +42,7 @@
                            CPDF_PageObjectHolder* pObjectHolder,
                            CPDF_Dictionary* pResources,
                            const CFX_FloatRect& rcBBox,
-                           CPDF_AllStates* pAllStates,
+                           const CPDF_AllStates* pAllStates,
                            std::set<const uint8_t*>* parsedSet);
   ~CPDF_StreamContentParser();