diff --git a/Runtime/MP1/World/CThardus.cpp b/Runtime/MP1/World/CThardus.cpp
index d0f8f6763..ae6c743a9 100644
--- a/Runtime/MP1/World/CThardus.cpp
+++ b/Runtime/MP1/World/CThardus.cpp
@@ -977,7 +977,7 @@ void CThardus::UpdateExcludeList(const std::unique_ptr<CCollisionActorManager>&
   }
 }
 
-void CThardus::RenderFlare(const CStateManager& mgr, float t) const {
+void CThardus::RenderFlare(const CStateManager& mgr, float t) {
   if (!x91c_flareTexture)
     return;
   if (!m_flareFilter)
diff --git a/Runtime/MP1/World/CThardus.hpp b/Runtime/MP1/World/CThardus.hpp
index 1fdb108b3..85a16cb14 100644
--- a/Runtime/MP1/World/CThardus.hpp
+++ b/Runtime/MP1/World/CThardus.hpp
@@ -159,11 +159,11 @@ class CThardus : public CPatterned {
   void _SetupCollisionManagers(CStateManager& mgr);
   void _BuildSphereJointList(const SSphereJointInfo* arr, size_t count, std::vector<CJointCollisionDescription>& list);
   void _BuildAABoxJointList(const SAABoxJointInfo* arr, size_t count, std::vector<CJointCollisionDescription>& list);
-  void RenderFlare(const CStateManager& mgr, float t) const;
+  void RenderFlare(const CStateManager& mgr, float t);
   zeus::CVector3f sub801de550(const CStateManager& mgr) const;
   zeus::CVector3f sub801de434(const CStateManager& mgr) const { return {}; }
 
-  mutable std::optional<CTexturedQuadFilter> m_flareFilter;
+  std::optional<CTexturedQuadFilter> m_flareFilter;
 
 public:
   DEFINE_PATTERNED(Thardus)