diff --git a/code/nel/tools/3d/lightmap_optimizer/main.cpp b/code/nel/tools/3d/lightmap_optimizer/main.cpp
index 2e1f0f47c..077cc83b5 100644
--- a/code/nel/tools/3d/lightmap_optimizer/main.cpp
+++ b/code/nel/tools/3d/lightmap_optimizer/main.cpp
@@ -998,7 +998,7 @@ int main(int nNbArg, char **ppArgs)
 		ChDir (sExeDir);
 
 		// out a text file, with list of
-		FILE *out = nlfopen(ppArgs[4], "wt");
+		FILE *out = NLMISC::nlfopen(ppArgs[4], "wt");
 
 		if(!out)
 		{