diff --git a/jstests/sharding/bf-28646.js b/jstests/sharding/bf-28646.js
new file mode 100644
index 00000000000..67124ecb850
--- /dev/null
+++ b/jstests/sharding/bf-28646.js
@@ -0,0 +1,45 @@
+(function() {
+'use strict';
+
+load('jstests/libs/fail_point_util.js');
+load('jstests/libs/parallel_shell_helpers.js');
+
+const dbName = 'test';
+const collName = 'foo';
+const ns = dbName + '.' + collName;
+
+const st = new ShardingTest({mongos: 1, shards: 2});
+
+st.adminCommand({enableSharding: dbName, primaryShard: st.shard0.shardName});
+st.adminCommand({shardCollection: ns, key: {x: 1}});
+
+// Set the 'hangBeforeSendingCommitDecision' failpoint on shard0.
+let fp = configureFailPoint(st.rs0.getPrimary(), 'hangBeforeSendingCommitDecision');
+
+// In a parallel shell, move a chunk to shard1.
+let awaitShell = startParallelShell(funWithArgs(function(ns, toShard) {
+                                        db.adminCommand({moveChunk: ns, find: {x: 0}, to: toShard});
+                                    }, ns, st.shard1.shardName), st.s.port);
+
+// Wait for the failpoint to be hit.
+fp.wait();
+jsTest.log("XXXX Hit fp");
+
+// Stepdown shard0 primary with force
+let shard0primary = st.rs0.getPrimary();
+assert.commandWorked(shard0primary.adminCommand({replSetStepDown: 5, force: true}));
+jsTest.log("XXXX Stepped down shard0 primary");
+
+// Wait for it to step up again.
+assert.soon(() => shard0primary.host === shard0primary.adminCommand('isMaster').primary);
+jsTest.log("XXXX Shard0 stepping up again");
+
+// Unset the failpoint
+jsTest.log("XXXX Unsetting the failpoint");
+fp.off();
+
+// Wait for the moveChunk to complete.
+awaitShell();
+
+st.stop();
+})();