diff --git a/Sources/Tools/MaxConvert/plMaxLightContext.h b/Sources/Tools/MaxConvert/plMaxLightContext.h
index 819987a5..3f6cdf8f 100644
--- a/Sources/Tools/MaxConvert/plMaxLightContext.h
+++ b/Sources/Tools/MaxConvert/plMaxLightContext.h
@@ -131,7 +131,7 @@ class plMaxRendContext : public RendContext
 public:
     Matrix3 WorldToCam() const { return Matrix3(1); }
     Color   GlobalLightLevel() const { return Color(1.f, 1.f, 1.f); }
-    int Progress(int done, int total) {
+    int Progress(int done, int total) const {
         return 1;
     }
 };
diff --git a/Sources/Tools/MaxConvert/plRenderGlobalContext.cpp b/Sources/Tools/MaxConvert/plRenderGlobalContext.cpp
index 94c4c159..442b0960 100644
--- a/Sources/Tools/MaxConvert/plRenderGlobalContext.cpp
+++ b/Sources/Tools/MaxConvert/plRenderGlobalContext.cpp
@@ -118,7 +118,7 @@ void plRenderGlobalContext::MakeRenderInstances(plMaxNode* root, TimeValue t)
         fInstList[i].SetNext(&fInstList[i+1]);
 }
 
-RenderInstance* plRenderGlobalContext::GetRenderInstance(int i) const
+RenderInstance* plRenderGlobalContext::GetRenderInstance(int i)
 {
     if (fInstList.GetCount() > i)
         return &fInstList[i];
diff --git a/Sources/Tools/MaxConvert/plRenderGlobalContext.h b/Sources/Tools/MaxConvert/plRenderGlobalContext.h
index a464cf6a..a5ee3cb9 100644
--- a/Sources/Tools/MaxConvert/plRenderGlobalContext.h
+++ b/Sources/Tools/MaxConvert/plRenderGlobalContext.h
@@ -62,8 +62,8 @@ public:
 
     void MakeRenderInstances(plMaxNode* root, TimeValue t);
 
-    virtual int NumRenderInstances() const { return fInstList.GetCount(); }
-    virtual RenderInstance* GetRenderInstance( int i ) const;
+    virtual int NumRenderInstances() { return fInstList.GetCount(); }
+    virtual RenderInstance* GetRenderInstance( int i );
 
     virtual void IntersectRay(RenderInstance *inst, Ray& ray, ISect &isct, ISectList &xpList, BOOL findExit);
     virtual BOOL IntersectWorld(Ray &ray, int skipID, ISect &hit, ISectList &xplist, int blurFrame = NO_MOTBLUR);