diff --git a/pyapacheatlas/core/client.py b/pyapacheatlas/core/client.py
index 115fc92..f70d13b 100644
--- a/pyapacheatlas/core/client.py
+++ b/pyapacheatlas/core/client.py
@@ -551,7 +551,7 @@ def get_typedef(self, type_category=None, guid=None, name=None):
             # business_Metadata has an underscore so before it can be used in
             # the endpoint, it must be converted to businessMetadata.
             atlas_endpoint = atlas_endpoint + \
-                "{}def".format(type_category.value.replace("_", ""))
+                "{}def".format(type_category.value.replace("_", "").lower())
         elif guid or name:
             atlas_endpoint = atlas_endpoint + "typedef"
         else: