diff --git a/src/napatrackmater/Trackmate.py b/src/napatrackmater/Trackmate.py
index 90dafb59..3bd91634 100644
--- a/src/napatrackmater/Trackmate.py
+++ b/src/napatrackmater/Trackmate.py
@@ -2911,7 +2911,7 @@ def prob_sigmoid(x):
 
 def angular_change(vec_mask, vec_cell):
 
-    vec = vec_cell - vec_mask
+    vec = np.asarray(vec_cell) - np.asarray(vec_mask)
     vec = vec / np.linalg.norm(vec)
     num_dimensions = len(vec)
     unit_vector = np.ones(num_dimensions) / num_dimensions
diff --git a/src/napatrackmater/_version.py b/src/napatrackmater/_version.py
index 6d8a84cd..56e8674d 100644
--- a/src/napatrackmater/_version.py
+++ b/src/napatrackmater/_version.py
@@ -1,2 +1,2 @@
-__version__ = version = "4.9.4"
-__version_tuple__ = version_tuple = (4, 9, 4)
+__version__ = version = "4.9.5"
+__version_tuple__ = version_tuple = (4, 9, 5)