diff --git a/flax/nnx/filterlib.py b/flax/nnx/filterlib.py
index f293b6cc0..824eb4315 100644
--- a/flax/nnx/filterlib.py
+++ b/flax/nnx/filterlib.py
@@ -89,13 +89,16 @@ def __repr__(self):
 
 @dataclasses.dataclass(frozen=True)
 class PathContains:
-  key: Key
+  key: Key | str
+  exact: bool = True
 
   def __call__(self, path: PathParts, x: tp.Any):
-    return self.key in path
+    if self.exact:
+      return self.key in path
+    return any(str(self.key) in str(part) for part in path)
 
   def __repr__(self):
-    return f'PathContains({self.key!r})'
+    return f'PathContains({self.key!r}, exact={self.exact})'
 
 
 class PathIn:
diff --git a/tests/nnx/filters_test.py b/tests/nnx/filters_test.py
index 94dcfda1e..f330c920b 100644
--- a/tests/nnx/filters_test.py
+++ b/tests/nnx/filters_test.py
@@ -21,15 +21,20 @@ class TestFilters(absltest.TestCase):
   def test_path_contains(self):
     class Model(nnx.Module):
       def __init__(self, rngs):
-        self.backbone = nnx.Linear(2, 3, rngs=rngs)
+        self.backbone1 = nnx.Linear(2, 3, rngs=rngs)
+        self.backbone2 = nnx.Linear(3, 3, rngs=rngs)
         self.head = nnx.Linear(3, 10, rngs=rngs)
 
     model = Model(nnx.Rngs(0))
 
     head_state = nnx.state(model, nnx.PathContains('head'))
+    backbones_state = nnx.state(model, nnx.PathContains('backbone', exact=False))
 
     self.assertIn('head', head_state)
     self.assertNotIn('backbone', head_state)
+    self.assertIn('backbone1', backbones_state)
+    self.assertIn('backbone2', backbones_state)
+    self.assertNotIn('head', backbones_state)
 
 if __name__ == '__main__':
   absltest.main()