diff --git a/addons/web_editor/controllers/main.py b/addons/web_editor/controllers/main.py
index bfd2ba177a5..ab8e583c5a0 100644
--- a/addons/web_editor/controllers/main.py
+++ b/addons/web_editor/controllers/main.py
@@ -49,7 +49,7 @@ class Web_Editor(http.Controller):
             :returns PNG image converted from given font
         """
         # Make sure we have at least size=1
-        size = max(1, size)
+        size = max(1, min(size, 512))
         # Initialize font
         addons_path = http.addons_manifest['web']['addons_path']
         font_obj = ImageFont.truetype(addons_path + font, size)