diff --git a/cdisc_rules_engine/operations/codelist_extensible.py b/cdisc_rules_engine/operations/codelist_extensible.py
index 1e7d91af3..62cd7b56f 100644
--- a/cdisc_rules_engine/operations/codelist_extensible.py
+++ b/cdisc_rules_engine/operations/codelist_extensible.py
@@ -26,6 +26,12 @@ def _handle_multiple_versions(self) -> pd.Series:
             self.params.ct_package_type, unique_ct_versions
         )
         ct_df = self.evaluation_dataset.__class__.from_dict(ct_data)
+        ct_df = ct_df.astype(
+            {
+                "version": "string",
+                "codelist_code": "string",
+            }
+        )
         if self.params.codelist_code in self.evaluation_dataset.columns:
             is_extensible = self.evaluation_dataset.merge(
                 ct_df.data,
diff --git a/cdisc_rules_engine/operations/codelist_terms.py b/cdisc_rules_engine/operations/codelist_terms.py
index 39707c3da..90a0a6d18 100644
--- a/cdisc_rules_engine/operations/codelist_terms.py
+++ b/cdisc_rules_engine/operations/codelist_terms.py
@@ -58,6 +58,12 @@ def _handle_multiple_versions(self) -> pd.Series:
             self.params.ct_package_type, unique_ct_versions
         )
         ct_df = self.evaluation_dataset.__class__.from_dict(ct_data)
+        ct_df = ct_df.astype(
+            {
+                "version": "string",
+                "codelist_code": "string",
+            }
+        )
         if self.params.codelist_code in self.evaluation_dataset.columns:
             result = self.evaluation_dataset.merge(
                 ct_df.data,
diff --git a/tests/unit/test_operations/test_codelist_extensible.py b/tests/unit/test_operations/test_codelist_extensible.py
index 38739ea8d..425a00d76 100644
--- a/tests/unit/test_operations/test_codelist_extensible.py
+++ b/tests/unit/test_operations/test_codelist_extensible.py
@@ -124,32 +124,44 @@ def test_empty_metadata(operation_params):
 
 
 @mark.parametrize(
-    "package_type, codelist_code, expected",
+    "package_type, codelist_code, versions, codelist_codes, expected",
     [
         (
             "mock_package",
             "codelist_code",
+            ["v1", "v2", "v3"],
+            ["C1", "C2", "C3"],
             [True, False, None],
         ),
         (
             "mock_package",
             "C1",
+            ["v1", "v2", "v3"],
+            ["C1", "C2", "C3"],
             [True, True, True],
         ),
         (
             "missing_package",
             "codelist_code",
+            ["v1", "v2", "v3"],
+            ["C1", "C2", "C3"],
             [None, None, None],
         ),
+        ("mock_package", "codelist_code", [], [], []),
     ],
 )
 def test_multiple_versions(
-    operation_params, mock_metadata, package_type, codelist_code, expected
+    operation_params,
+    mock_metadata,
+    package_type,
+    codelist_code,
+    versions,
+    codelist_codes,
+    expected,
 ):
     operation_params.ct_package_type = package_type
     operation_params.ct_version = "version"
     operation_params.codelist_code = codelist_code
-    versions = ["v1", "v2", "v3"]
 
     library_metadata = LibraryMetadataContainer()
     for version in versions:
@@ -157,7 +169,7 @@ def test_multiple_versions(
     library_metadata._ct_package_metadata = mock_metadata
 
     evaluation_dataset = PandasDataset.from_dict(
-        {"version": versions, "codelist_code": ["C1", "C2", "C3"]}
+        {"version": versions, "codelist_code": codelist_codes}
     )
 
     operation = CodelistExtensible(
diff --git a/tests/unit/test_operations/test_codelist_terms.py b/tests/unit/test_operations/test_codelist_terms.py
index cf27e7f14..d0fb1811c 100644
--- a/tests/unit/test_operations/test_codelist_terms.py
+++ b/tests/unit/test_operations/test_codelist_terms.py
@@ -323,3 +323,39 @@ def test_multiple_versions(
     except RuleExecutionError:
         result = pd.Series(RuleExecutionError)
     assert result.equals(pd.Series(expected))
+
+
+def test_empty_dataset_multiple_versions(
+    operation_params,
+    mock_metadata,
+):
+    operation_params.ct_package_type = "mock_package"
+    operation_params.ct_version = "version"
+    operation_params.codelist_code = "codelist_code"
+    operation_params.term_code = "t_code"
+    operation_params.term_value = None
+    operation_params.term_pref_term = None
+    operation_params.returntype = None
+
+    library_metadata = LibraryMetadataContainer()
+    library_metadata._ct_package_metadata = mock_metadata
+
+    evaluation_dataset = PandasDataset.from_dict(
+        {
+            "version": [],
+            "codelist_code": [],
+            "t_code": [],
+            "t_value": [],
+            "t_pref_term": [],
+        }
+    )
+
+    operation = CodelistTerms(
+        operation_params,
+        evaluation_dataset,
+        MagicMock(),
+        MagicMock(),
+        library_metadata,
+    )
+    result = operation._execute_operation()
+    assert result.tolist() == []