diff --git a/qa/workunits/mon/pool_ops.sh b/qa/workunits/mon/pool_ops.sh
index a336fd544e7..4098795b989 100755
--- a/qa/workunits/mon/pool_ops.sh
+++ b/qa/workunits/mon/pool_ops.sh
@@ -25,6 +25,16 @@ ceph osd pool set foo size 10
 expect_false ceph osd pool set foo size 0
 expect_false ceph osd pool set foo size 20
 
+ceph osd pool set foo size 3
+ceph osd getcrushmap -o crush
+crushtool -d crush -o crush.txt
+sed -i 's/max_size 10/max_size 3/' crush.txt
+crushtool -c crush.txt -o crush.new
+ceph osd setcrushmap -i crush.new
+expect_false ceph osd pool set foo size 4
+ceph osd setcrushmap -i crush
+rm -f crush crush.txt crush.new
+
 # should fail due to safety interlock
 expect_false ceph osd pool delete foo
 expect_false ceph osd pool delete foo foo