diff -ruN a/bottle.py b/bottle.py
--- a/bottle.py	2023-03-04 16:33:42.000000000 +0100
+++ b/bottle.py	2023-06-28 09:52:43.757114094 +0200
@@ -1803,10 +1803,15 @@
                                     '__all__': [], '__loader__': self})
         sys.meta_path.append(self)
 
+    def find_spec(self, fullname, path, target=None):
+        if '.' not in fullname: return
+        if fullname.rsplit('.', 1)[0] != self.name: return
+        from importlib.util import spec_from_loader
+        return spec_from_loader(fullname, self)
+
     def find_module(self, fullname, path=None):
         if '.' not in fullname: return
-        packname = fullname.rsplit('.', 1)[0]
-        if packname != self.name: return
+        if fullname.rsplit('.', 1)[0] != self.name: return
         return self
 
     def load_module(self, fullname):