diff --git a/bsb/simulators/arbor/__init__.py b/bsb/simulators/arbor/__init__.py
index 5985a4034..6afd91387 100644
--- a/bsb/simulators/arbor/__init__.py
+++ b/bsb/simulators/arbor/__init__.py
@@ -1,3 +1,26 @@
+import types
+
+# fixme: Once this adapter is moved to bsb-arbor, arbor can be a hard dependency at import
+#  time, and this code can be removed.
+try:
+    import arbor
+except ImportError as e:
+    import sys
+    from bsb.reporting import warn
+
+    errmsg = f"Can't use bsb-arbor: Arbor is not importable: {e}"
+    warn(errmsg)
+
+    class ArborMock(types.ModuleType):
+        class recipe:
+            def __getattr__(self, item):
+                raise AttributeError(errmsg)
+
+        def __getattr__(self, item):
+            raise AttributeError(errmsg)
+
+    sys.modules["arbor"] = ArborMock(name="arbor")
+
 from bsb.simulation import SimulationBackendPlugin
 from .simulation import ArborSimulation
 from .adapter import ArborAdapter