diff --git a/aas_test_engines/_generate.py b/aas_test_engines/_generate.py
index 9208e95..5f5bacf 100644
--- a/aas_test_engines/_generate.py
+++ b/aas_test_engines/_generate.py
@@ -249,10 +249,10 @@ def apply(self, data: KeyReference) -> any:
 def generate_graph(schema) -> FlowGraph:
     norm_config = NormalizationConfig(
         full_merge=False,
-        discard_fields={'discriminator'},
         additional_mergers={
             'check': lambda x, y: x + y
-        }
+        },
+        detect_duplicate_subschemas=True,
     )
     schema_norm = normalize(schema, norm_config)
     config = default_config()
diff --git a/requirements.txt b/requirements.txt
index 7df5ece..4e8d09b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,4 +2,4 @@ requests>=2.31
 pyyaml>=6.0
 json_schema_tool>=0.4
 jsonpath_ng>=1.5
-fences==1.2.0
+fences==1.3.0