diff --git a/source/exercises100.ktx b/source/exercises100.ktx
index cb8f463..5d2aea9 100644
--- a/source/exercises100.ktx
+++ b/source/exercises100.ktx
@@ -1041,7 +1041,7 @@ from numpy.lib import stride_tricks
 
 def rolling(a, window):
     shape = (a.size - window + 1, window)
-    strides = (a.itemsize, a.itemsize)
+    strides = (a.strides[0], a.strides[0])
     return stride_tricks.as_strided(a, shape=shape, strides=strides)
 Z = rolling(np.arange(10), 3)
 print(Z)