diff --git a/src/ansys/rocky/core/client.py b/src/ansys/rocky/core/client.py
index 38ad4cdc..7fab3cc2 100644
--- a/src/ansys/rocky/core/client.py
+++ b/src/ansys/rocky/core/client.py
@@ -36,9 +36,6 @@
 
 DEFAULT_SERVER_PORT: Final[int] = 50615
 _ROCKY_API: Pyro5.api.Proxy | None = None
-_ROCKY_VERSION: int | None = (
-    None  # Rocky version as integer (24R2 becomes 242, 25R1 becomes 251, ...)
-)
 
 
 def connect_to_rocky(
@@ -60,13 +57,12 @@ def connect_to_rocky(
         Client object for interacting with the Rocky app.
     """
     uri = f"PYRO:rocky.api@{host}:{port}"
-    global _ROCKY_API, _ROCKY_VERSION
+    global _ROCKY_API
 
     if _ROCKY_API is None:
         register_proxies()
 
     _ROCKY_API = Pyro5.api.Proxy(uri)
-    _ROCKY_VERSION = _get_numerical_version(_ROCKY_API)
 
     rocky_client = RockyClient(_ROCKY_API)
     return rocky_client
diff --git a/src/ansys/rocky/core/serializers.py b/src/ansys/rocky/core/serializers.py
index 9f6e58b9..397893f4 100644
--- a/src/ansys/rocky/core/serializers.py
+++ b/src/ansys/rocky/core/serializers.py
@@ -57,11 +57,12 @@ def _ApiElementProxySerializer(obj: ApiElementProxy) -> dict:
     Serialize an `ApiElementProxy` ensuring backward compatibility with
     ROCKY 24.2 and older versions.
     """
-    from .client import _ROCKY_VERSION
+    from ansys.rocky.core.client import _ROCKY_API, _get_numerical_version
 
+    ROCKY_VERSION = _get_numerical_version(_ROCKY_API)
     serialized = ApiElementProxy.serialize(obj)
 
-    if _ROCKY_VERSION is not None and _ROCKY_VERSION < 250:
+    if ROCKY_VERSION is not None and ROCKY_VERSION < 250:
         serialized["__class__"] = f'_{serialized["__class__"]}'
     return serialized
 
diff --git a/tests/test_pyrocky.py b/tests/test_pyrocky.py
index 7e0a4dce..b4dc8e90 100644
--- a/tests/test_pyrocky.py
+++ b/tests/test_pyrocky.py
@@ -80,10 +80,10 @@ def test_minimal_simulation(version, expected_version, tmp_path, request):
     rocky = pyrocky.connect_to_rocky()
     request.addfinalizer(rocky.close)
 
-    from ansys.rocky.core.client import _ROCKY_VERSION
+    from ansys.rocky.core.client import _ROCKY_API, _get_numerical_version
 
-    global _ROCKY_VERSION
-    assert _ROCKY_VERSION == expected_version
+    ROCKY_VERSION = _get_numerical_version(_ROCKY_API)
+    assert ROCKY_VERSION == expected_version
 
     study = create_basic_project_with_results(
         rocky.api, str(tmp_path / "rocky-testing.rocky")