diff --git a/ultrack/utils/cuda.py b/ultrack/utils/cuda.py
index 4c8ae4b..43552ae 100644
--- a/ultrack/utils/cuda.py
+++ b/ultrack/utils/cuda.py
@@ -19,6 +19,7 @@
 
     if not cp.cuda.is_available():
         cp = None
+        xp = np
         LOG.info("cupy found but cuda is not available.")
     else:
         from cupy.cuda.memory import malloc_managed