diff --git a/src/compas_fab/backends/__init__.py b/src/compas_fab/backends/__init__.py
index 74a67525b..9501fdb16 100644
--- a/src/compas_fab/backends/__init__.py
+++ b/src/compas_fab/backends/__init__.py
@@ -147,13 +147,16 @@
     Staubli_TX260LKinematics,
     ABB_IRB4600_40_255Kinematics,
 )
-from .pybullet import (
-    PyBulletClient,
-    CollisionError,
-    PyBulletError,
-    PyBulletPlanner,
-    AnalyticalPyBulletClient,
-)
+
+if not compas.IPY:
+    # PyBullet do not work in IronPython
+    from .pybullet import (
+        PyBulletClient,
+        CollisionError,
+        PyBulletError,
+        PyBulletPlanner,
+        AnalyticalPyBulletClient,
+    )
 
 __all__ = [
     # Base