diff --git a/src/google/adk/evaluation/conversation_scenarios.py b/src/google/adk/evaluation/conversation_scenarios.py
index e74ae3b1..dc2d09b7 100644
--- a/src/google/adk/evaluation/conversation_scenarios.py
+++ b/src/google/adk/evaluation/conversation_scenarios.py
@@ -20,7 +20,7 @@ from pydantic import Field
 from pydantic import field_validator
 
 from .common import EvalBaseModel
-from .simulation.pre_built_personas import DEFAULT_USER_PERSONA_REGISTRY
+from .simulation.pre_built_personas import get_default_persona_registry
 from .simulation.user_simulator_personas import UserPersona
 
 
@@ -62,7 +62,7 @@ class ConversationScenario(EvalBaseModel):
       cls, value: Optional[UserPersona | str]
   ) -> Optional[UserPersona]:
     if value is not None and isinstance(value, str):
-      return DEFAULT_USER_PERSONA_REGISTRY.get_persona(value)
+      return get_default_persona_registry().get_persona(value)
     return value
 
 
diff --git a/src/google/adk/evaluation/simulation/pre_built_personas.py b/src/google/adk/evaluation/simulation/pre_built_personas.py
index 63f3f25e..03f52ae6 100644
--- a/src/google/adk/evaluation/simulation/pre_built_personas.py
+++ b/src/google/adk/evaluation/simulation/pre_built_personas.py
@@ -509,7 +509,7 @@ class _PreBuiltPersonas(enum.Enum):
   )
 
 
-def _get_default_persona_registry() -> UserPersonaRegistry:
+def get_default_persona_registry() -> UserPersonaRegistry:
   registry = UserPersonaRegistry()
 
   registry.register_persona(
@@ -523,6 +523,3 @@ def _get_default_persona_registry() -> UserPersonaRegistry:
   )
 
   return registry
-
-
-DEFAULT_USER_PERSONA_REGISTRY = _get_default_persona_registry()
diff --git a/tests/unittests/evaluation/simulation/test_pre_built_personas.py b/tests/unittests/evaluation/simulation/test_pre_built_personas.py
index f83fdd88..32401da4 100644
--- a/tests/unittests/evaluation/simulation/test_pre_built_personas.py
+++ b/tests/unittests/evaluation/simulation/test_pre_built_personas.py
@@ -12,9 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from google.adk.evaluation.simulation import pre_built_personas
+from google.adk.evaluation.simulation.pre_built_personas import get_default_persona_registry
 
 
 def test_get_default_persona_registry():
   """Tests that the default persona registry can be loaded."""
-  assert pre_built_personas.DEFAULT_USER_PERSONA_REGISTRY is not None
+  assert get_default_persona_registry() is not None