diff --git a/canaille/__init__.py b/canaille/__init__.py
index 5d42f7b3..a6a05fd8 100644
--- a/canaille/__init__.py
+++ b/canaille/__init__.py
@@ -53,6 +53,8 @@ def setup_blueprints(app):
 
 
 def setup_flask(app):
+    from canaille.app.themes import render_template
+
     csrf.init_app(app)
 
     @app.before_request
@@ -76,6 +78,26 @@ def setup_flask(app):
             "features": app.features,
         }
 
+    @app.errorhandler(400)
+    def bad_request(error):
+        return render_template("error.html", description=error, error_code=400), 400
+
+    @app.errorhandler(403)
+    def unauthorized(error):
+        return render_template("error.html", description=error, error_code=403), 403
+
+    @app.errorhandler(404)
+    def page_not_found(error):
+        from canaille.app.flask import redirect_to_bp_handlers
+
+        return redirect_to_bp_handlers(app, error) or render_template(
+            "error.html", description=error, error_code=404
+        ), 404
+
+    @app.errorhandler(500)
+    def server_error(error):  # pragma: no cover
+        return render_template("error.html", description=error, error_code=500), 500
+
 
 def setup_flask_converters(app):
     from canaille.app import models
diff --git a/canaille/app/themes.py b/canaille/app/themes.py
index f5139b1a..db37483d 100644
--- a/canaille/app/themes.py
+++ b/canaille/app/themes.py
@@ -30,33 +30,6 @@ if flask_themer:
             # if config['THEME'] may be a theme name or a path
             return app.config["CANAILLE"]["THEME"].split("/")[-1]
 
-        @app.errorhandler(400)
-        def bad_request(error):
-            return render_template("error.html", description=error, error_code=400), 400
-
-        @app.errorhandler(403)
-        def unauthorized(error):
-            return render_template("error.html", description=error, error_code=403), 403
-
-        @app.errorhandler(404)
-        def page_not_found(error):
-            from canaille.app.flask import redirect_to_bp_handlers
-
-            return redirect_to_bp_handlers(app, error) or render_template(
-                "error.html", description=error, error_code=404
-            ), 404
-
-        @app.errorhandler(500)
-        def server_error(error):  # pragma: no cover
-            return render_template("error.html", description=error, error_code=500), 500
 
 else:  # pragma: no cover
     render_template = flask.render_template
-
-    def setup_themer(app):
-        @app.errorhandler(404)
-        def page_not_found(error):
-            from canaille.app.flask import redirect_to_bp_handlers
-
-            if not redirect_to_bp_handlers(app, error):
-                raise error