diff --git a/changedetectionio/api/Watch.py b/changedetectionio/api/Watch.py
index 9f5d0c82..5acc626f 100644
--- a/changedetectionio/api/Watch.py
+++ b/changedetectionio/api/Watch.py
@@ -447,6 +447,9 @@ class WatchFavicon(Resource):
             # Use cached MIME type detection
             filepath = os.path.join(watch.data_dir, favicon_filename)
             mime = get_favicon_mime_type(filepath)
+            if 'text' in mime:
+                logger.debug(f"Aborting favicon request for {filepath} because mimetype might be text (bad mimetype) '{mime}'")
+                abort(404)
 
             response = make_response(send_from_directory(watch.data_dir, favicon_filename))
             response.headers['Content-type'] = mime
diff --git a/changedetectionio/flask_app.py b/changedetectionio/flask_app.py
index b1b1b0de..f8155f85 100644
--- a/changedetectionio/flask_app.py
+++ b/changedetectionio/flask_app.py
@@ -789,7 +789,11 @@ def changedetection_app(config=None, datastore_o=None):
             if favicon_filename:
                 # Use cached MIME type detection
                 filepath = os.path.join(watch.data_dir, favicon_filename)
+
                 mime = get_favicon_mime_type(filepath)
+                if 'text' in mime:
+                    logger.debug(f"Aborting favicon request for {filename} because mimetype might be text (bad mimetype) '{mime}'")
+                    abort(404)
 
                 response = make_response(send_from_directory(watch.data_dir, favicon_filename))
                 response.headers['Content-type'] = mime