diff --git a/cuburn/code/mwc.py b/cuburn/code/mwc.py
index dc12c32..c24726e 100644
--- a/cuburn/code/mwc.py
+++ b/cuburn/code/mwc.py
@@ -102,14 +102,14 @@ def test_mwc(rounds=5000, nblocks=64, blockwidth=512):
         print "Trial %d, on CPU: " % trial,
         sums = np.zeros(nthreads, dtype=np.uint64)
         ctime = time.time()
-        mults = seeds[0].astype(np.uint64)
-        states = seeds[1]
-        carries = seeds[2]
+        mults = seeds[:,0].astype(np.uint64)
+        states = seeds[:,1]
+        carries = seeds[:,2]
         for i in range(rounds):
             step = np.frombuffer((mults * states + carries).data,
-                       dtype=np.uint32).reshape((2, nthreads), order='F')
-            states[:] = step[0]
-            carries[:] = step[1]
+                       dtype=np.uint32).reshape((nthreads, 2))
+            states[:] = step[:,0]
+            carries[:] = step[:,1]
             sums += states
 
         ctime = time.time() - ctime