diff --git a/trx/tests/test_memmap.py b/trx/tests/test_memmap.py
index 0d9488f..21451a4 100644
--- a/trx/tests/test_memmap.py
+++ b/trx/tests/test_memmap.py
@@ -398,6 +398,26 @@ def test_trxfile_close():
     pass
 
 
+@pytest.mark.parametrize("path", [("small.trx")])
+def test_close_releases_mmap_from_zip(path):
+    """close() must release mmap handles even when loaded via load_from_zip()."""
+    path = os.path.join(get_home(), "memmap_test_data", path)
+    trx = tmm.load_from_zip(path)
+
+    assert trx._uncompressed_folder_handle is None
+
+    mmap_obj = trx.streamlines._data._mmap
+    assert mmap_obj is not None, "expected a live mmap before close()"
+    assert not mmap_obj.closed, "mmap should be open before close()"
+
+    trx.close()
+
+    assert mmap_obj.closed, (
+        "mmap is still open after close() — the mmap teardown was skipped "
+        "because _uncompressed_folder_handle was None"
+    )
+
+
 # Endianness tests for cross-platform compatibility (Issue #83)
 @pytest.mark.parametrize(
     "dtype_input,expected_byteorder",
diff --git a/trx/trx_file_memmap.py b/trx/trx_file_memmap.py
index d6aa485..1556f59 100644
--- a/trx/trx_file_memmap.py
+++ b/trx/trx_file_memmap.py
@@ -2260,23 +2260,22 @@ def close(self) -> None:
         None
             Releases file handles and removes temporary storage.
         """
-        if self._uncompressed_folder_handle is not None:
-            close_or_delete_mmap(self.streamlines)
+        close_or_delete_mmap(self.streamlines)
 
-            # # Close or delete attributes in dictionaries
-            for key in self.data_per_vertex:
-                close_or_delete_mmap(self.data_per_vertex[key])
+        for key in self.data_per_vertex:
+            close_or_delete_mmap(self.data_per_vertex[key])
 
-            for key in self.data_per_streamline:
-                close_or_delete_mmap(self.data_per_streamline[key])
+        for key in self.data_per_streamline:
+            close_or_delete_mmap(self.data_per_streamline[key])
 
-            for key in self.groups:
-                close_or_delete_mmap(self.groups[key])
+        for key in self.groups:
+            close_or_delete_mmap(self.groups[key])
 
-            for key in self.data_per_group:
-                for dpg in self.data_per_group[key]:
-                    close_or_delete_mmap(self.data_per_group[key][dpg])
+        for key in self.data_per_group:
+            for dpg in self.data_per_group[key]:
+                close_or_delete_mmap(self.data_per_group[key][dpg])
 
+        if self._uncompressed_folder_handle is not None:
             try:
                 self._uncompressed_folder_handle.cleanup()
             except PermissionError: