diff --git a/just_psf/geometry.py b/just_psf/geometry.py
index 12852ef..cc5d8d5 100644
--- a/just_psf/geometry.py
+++ b/just_psf/geometry.py
@@ -1,6 +1,6 @@
 import numpy
 
-from typing import TextIO, Self
+from typing import TextIO
 from just_psf import logger
 
 
@@ -17,8 +17,8 @@ def __init__(self, symbols: list, positions: numpy.ndarray):
     def __len__(self) -> int:
         return len(self.symbols)
 
-    def copy(self) -> Self:
-        """Copy itself. Involves a copy of positions, symbols, and unit cell.
+    def copy(self) -> 'Geometry':
+        """Copy itself. Involves a copy of positions and symbols.
         """
 
         return Geometry(
@@ -27,7 +27,7 @@ def copy(self) -> Self:
         )
 
     @classmethod
-    def from_xyz(cls, f: TextIO) -> Self:
+    def from_xyz(cls, f: TextIO) -> 'Geometry':
         """Read geometry from a XYZ file
         """
 
diff --git a/just_psf/topology.py b/just_psf/topology.py
index 79d36f4..f724936 100644
--- a/just_psf/topology.py
+++ b/just_psf/topology.py
@@ -1,7 +1,7 @@
 import numpy
 from numpy.typing import NDArray
 
-from typing import TextIO, List, Self, Optional
+from typing import TextIO, List, Optional
 
 
 class Topology:
@@ -59,7 +59,7 @@ def __len__(self) -> int:
         return len(self.symbols)
 
     @classmethod
-    def from_psf(cls, f: TextIO) -> Self:
+    def from_psf(cls, f: TextIO) -> 'Topology':
         """Read topology from a NAMD PSF file"""
 
         from just_psf.psf_parser import PSFParser