diff --git a/Sandboxie/core/dll/rpcrt.c b/Sandboxie/core/dll/rpcrt.c
index ce39cea9..b8641bbf 100644
--- a/Sandboxie/core/dll/rpcrt.c
+++ b/Sandboxie/core/dll/rpcrt.c
@@ -844,7 +844,7 @@ RPC_STATUS RPC_ENTRY RpcRt_RpcStringBindingComposeW(TCHAR *ObjUuid,TCHAR *ProtSe
 
 void Sbie_StringFromGUID(const GUID* guid, WCHAR* str);
 
-void RpcRt_NdrClientCallX(const WCHAR* Function, void* ReturnAddress,PMIDL_STUB_DESC pStubDescriptor, void* pFormat)
+void RpcRt_NdrClientCallX(const WCHAR* Function, void* ReturnAddress,PMIDL_STUB_DESC pStubDescriptor, const void* pFormat)
 {
     WCHAR text[512] = L"RpcRt_NdrClientCallX";
     __try
diff --git a/Sandboxie/core/dll/secure.c b/Sandboxie/core/dll/secure.c
index 18373324..023e7394 100644
--- a/Sandboxie/core/dll/secure.c
+++ b/Sandboxie/core/dll/secure.c
@@ -1783,7 +1783,7 @@ ALIGNED BOOLEAN __cdecl Secure_CheckElevation64(
 #endif _WIN64
 
 extern BOOLEAN g_rpc_client_hooks;
-void RpcRt_NdrClientCallX(const WCHAR* Function, void* ReturnAddress, VOID* pStubDescriptor, void* pFormat);
+void RpcRt_NdrClientCallX(const WCHAR* Function, void* ReturnAddress, VOID* pStubDescriptor, const void* pFormat);
 
 ALIGNED BOOLEAN __cdecl Secure_CheckElevation(
     void *ReturnAddressFromNdrAsyncClientCall,