diff --git a/test/test_imagewrapper.py b/test/test_imagewrapper.py
index f235e006cad346298c6f43d537700b40d621db27..2280fabc0eb42cc44db2bf0ca434ea149b4b5b82 100644
--- a/test/test_imagewrapper.py
+++ b/test/test_imagewrapper.py
@@ -259,7 +259,7 @@ def _test_expansion(coverage, slices, volumes, expansions):
     # coverage, or in one of the expansions.
     dimranges = []
     for d in range(ndims):
-        dimranges.append(np.arange(nc[0, d], nc[1, d]))
+        dimranges.append(np.linspace(nc[0, d], nc[1, d], nc[1, d] / 5, dtype=np.uint32))
 
     points = it.product(*dimranges)