diff --git a/code/nel/tools/3d/plugin_max/nel_patch_edit/np_epm_tess.cpp b/code/nel/tools/3d/plugin_max/nel_patch_edit/np_epm_tess.cpp
index 0823afbd4..9cfe2ff95 100644
--- a/code/nel/tools/3d/plugin_max/nel_patch_edit/np_epm_tess.cpp
+++ b/code/nel/tools/3d/plugin_max/nel_patch_edit/np_epm_tess.cpp
@@ -223,7 +223,7 @@ BOOL CALLBACK PatchObjSurfDlgProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM
 
 		 	ep =(EditPatchMod *)lParam;
 		 	ep->hSurfPanel = hDlg;
-			SetWindowLongPtr(hDlg, GWLP_USERDATA, (LONG)ep);		 	
+			SetWindowLongPtr(hDlg, GWLP_USERDATA, (LONG_PTR)ep);		 	
 			if (!ep->settingViewportTess  && ep->settingDisp && ep->GetProdTess().type == TESS_SET)
 				ep->settingDisp = FALSE;
 			TessApprox t;