diff --git a/code/nel/tools/3d/textures_optimizer/main.cpp b/code/nel/tools/3d/textures_optimizer/main.cpp
index 8ecffedab..022709444 100644
--- a/code/nel/tools/3d/textures_optimizer/main.cpp
+++ b/code/nel/tools/3d/textures_optimizer/main.cpp
@@ -131,6 +131,9 @@ int main(int argc, char **argv)
 
 		NLMISC::CBitmap bitmap;
 
+		// all 8 bits textures are grayscale and not alpha
+		bitmap.loadGrayscaleAsAlpha(false);
+
 		uint8 depth = bitmap.load(input);
 
 		// don't need file so close it