diff --git a/pytest_mypy_plugins/item.py b/pytest_mypy_plugins/item.py
index be50b1f..922f400 100644
--- a/pytest_mypy_plugins/item.py
+++ b/pytest_mypy_plugins/item.py
@@ -401,7 +401,11 @@ def remove_cache_files(self, fpath_no_suffix: Path) -> None:
                         pass
                 store.commit()
             finally:
-                store.close()
+                # ``MetadataStore.close`` was added in mypy 1.20; guard for older
+                # mypy versions that are still within our supported range (>=1.3).
+                close = getattr(store, "close", None)
+                if close is not None:
+                    close()
 
     def execute_extension_hook(self) -> None:
         extension_hook_fqname = self.config.option.mypy_extension_hook
diff --git a/pytest_mypy_plugins/tests/test_mypy_cache.py b/pytest_mypy_plugins/tests/test_mypy_cache.py
index 22773d3..70aac48 100644
--- a/pytest_mypy_plugins/tests/test_mypy_cache.py
+++ b/pytest_mypy_plugins/tests/test_mypy_cache.py
@@ -224,6 +224,9 @@ def get_created_cache_files(cache_dir: Path, module_rel_paths_no_suffix: tuple[s
                 if any(entry.startswith(rel_path + ".") for rel_path in module_rel_paths_no_suffix):
                     created.append(entry)
         finally:
-            store.close()
+            # See PR #188: mypy < 1.20 does not have MetadataStore.close
+            close = getattr(store, "close", None)
+            if close is not None:
+                close()
 
     return created