diff --git a/superset/models/core.py b/superset/models/core.py
index 23276181b4b31..5d0dde3dce9b7 100755
--- a/superset/models/core.py
+++ b/superset/models/core.py
@@ -632,7 +632,10 @@ def get_indexes(
     def get_pk_constraint(
         self, table_name: str, schema: Optional[str] = None
     ) -> Dict[str, Any]:
-        return self.inspector.get_pk_constraint(table_name, schema)
+        pk_constraint = self.inspector.get_pk_constraint(table_name, schema) or {}
+        return {
+            key: utils.base_json_conv(value) for key, value in pk_constraint.items()
+        }
 
     def get_foreign_keys(
         self, table_name: str, schema: Optional[str] = None