diff --git a/src/qonnx/transformation/create_generic_partitions.py b/src/qonnx/transformation/create_generic_partitions.py
index bc6ea7d7..999d4efe 100755
--- a/src/qonnx/transformation/create_generic_partitions.py
+++ b/src/qonnx/transformation/create_generic_partitions.py
@@ -195,13 +195,14 @@ def __init__(self, partitioning={}, partition_dir=None):
     def apply(self, model):
         # prepare node -> int assignment fct.
         def partitioning_func(node):
-            partition_id = -1
-            for key in self.partitioning:
-                if node in list(model.graph.node) and list(model.graph.node).index(node) in list(self.partitioning[key]):
-                    assert partition_id == -1, """single node assigned to multiple partitions"""
-                    partition_id = key
-
-            return partition_id
+            if node not in model.graph.node:
+                return -1
+            node_index = list(model.graph.node).index(node)
+            candidates = list(filter(lambda key_value: node_index in key_value[1], self.partitioning.items()))
+            if len(candidates) == 0:
+                return -1
+            assert len(candidates) == 1, f"single node assigned to multiple partitions: {candidates}"
+            return candidates[0][0]  # partition_id
 
         # apply partitioning
         model = model.transform(PartitionFromLambda(partitioning_func, self.partition_dir))