diff --git a/examples/src/main/python/als.py b/examples/src/main/python/als.py
index 1c3a787bd0e94..205ca02962bee 100755
--- a/examples/src/main/python/als.py
+++ b/examples/src/main/python/als.py
@@ -36,7 +36,7 @@
 
 def rmse(R, ms, us):
     diff = R - ms * us.T
-    return np.sqrt(np.sum(np.power(diff, 2)) / M * U)
+    return np.sqrt(np.sum(np.power(diff, 2)) / (M * U))
 
 
 def update(i, vec, mat, ratings):