diff --git a/.circleci/config.yml b/.circleci/config.yml
index 7d162293..25db2ba6 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -10,7 +10,7 @@ executors:
 
   machine-executor:
     machine:
-      image: ubuntu-2404:2024.05.1
+      image: ubuntu-2404:current
 
 jobs:
   lint:
@@ -43,6 +43,9 @@ jobs:
           command: mypy $PACKAGE_DIR $TESTS_DIR
 
   test:
+    parameters:
+      python_version:
+        type: string
     executor: machine-executor
     steps:
       - checkout
@@ -57,8 +60,8 @@ jobs:
           name: Setup Python
           command: |
             pyenv --version
-            pyenv install -f 3.10
-            pyenv global 3.10
+            pyenv install -f << parameters.python_version >>
+            pyenv global << parameters.python_version >>
 
       - run:
           name: Setup pip
@@ -81,4 +84,7 @@ workflows:
   build:
     jobs:
       - lint
-      - test
\ No newline at end of file
+      - test:
+          matrix:
+            parameters:
+              python_version: ["3.10", "3.11", "3.12.2"]
\ No newline at end of file
diff --git a/nx_arangodb/classes/dict/adj.py b/nx_arangodb/classes/dict/adj.py
index 32280e95..380584eb 100644
--- a/nx_arangodb/classes/dict/adj.py
+++ b/nx_arangodb/classes/dict/adj.py
@@ -432,6 +432,11 @@ def __contains__(self, key: str | int) -> bool:
         'edge/1' in G._adj['node/1']['node/2']
         0 in G._adj['node/1']['node/2']
         """
+        # HACK: This is a workaround for the fact that
+        # nxadb.MultiGraph does not yet support custom edge keys
+        if key == "-1":
+            return False
+
         if isinstance(key, int):
             key = self.__process_int_edge_key(key)
 
@@ -464,7 +469,7 @@ def __contains__(self, key: str | int) -> bool:
     def __getitem__(self, key: str | int) -> EdgeAttrDict:
         """G._adj['node/1']['node/2']['edge/1']"""
         # HACK: This is a workaround for the fact that
-        # nxadb.MultiGraph does not yet support edge keys
+        # nxadb.MultiGraph does not yet support custom edge keys
         if key == "-1":
             raise KeyError(key)