diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java
index a006d166b67..dff8e64c041 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java
@@ -3165,6 +3165,8 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
         if (serverName == null) {
           future.completeExceptionally(
             new IllegalArgumentException(String.format("Null ServerName: %s", regionServerName)));
+        } else {
+          serverList.add(serverName);
         }
       }
       future.complete(serverList);
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAsyncRegionAdminApi.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAsyncRegionAdminApi.java
index 28e60d2f957..aeff96e8964 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAsyncRegionAdminApi.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAsyncRegionAdminApi.java
@@ -335,6 +335,26 @@ public class TestAsyncRegionAdminApi extends TestAsyncAdminBase {
       assertEquals("Last compaction state, expected=disabled actual=enabled",
           false, p.getValue());
     }
+    ServerName serverName = TEST_UTIL.getHBaseCluster().getRegionServer(0)
+        .getServerName();
+    List<String> serverNameList = new ArrayList<String>();
+    serverNameList.add(serverName.getServerName());
+    CompletableFuture<Map<ServerName, Boolean>> listCompletableFuture3 =
+        admin.compactionSwitch(false, serverNameList);
+    Map<ServerName, Boolean> pairs3 = listCompletableFuture3.get();
+    assertEquals(pairs3.entrySet().size(), 1);
+    for (Map.Entry<ServerName, Boolean> p : pairs3.entrySet()) {
+      assertEquals("Last compaction state, expected=enabled actual=disabled",
+          true, p.getValue());
+    }
+    CompletableFuture<Map<ServerName, Boolean>> listCompletableFuture4 =
+        admin.compactionSwitch(true, serverNameList);
+    Map<ServerName, Boolean> pairs4 = listCompletableFuture4.get();
+    assertEquals(pairs4.entrySet().size(), 1);
+    for (Map.Entry<ServerName, Boolean> p : pairs4.entrySet()) {
+      assertEquals("Last compaction state, expected=disabled actual=enabled",
+          false, p.getValue());
+    }
   }
 
   @Test
diff --git a/hbase-shell/src/main/ruby/shell/commands/compaction_switch.rb b/hbase-shell/src/main/ruby/shell/commands/compaction_switch.rb
index 94db700bc87..6a58bbe5d56 100644
--- a/hbase-shell/src/main/ruby/shell/commands/compaction_switch.rb
+++ b/hbase-shell/src/main/ruby/shell/commands/compaction_switch.rb
@@ -33,9 +33,9 @@ module Shell
             To disable compactions on all region servers
             hbase> compaction_switch false
             To enable compactions on specific region servers
-            hbase> compaction_switch true 'server2','server1'
+            hbase> compaction_switch true, 'server2','server1'
             To disable compactions on specific region servers
-            hbase> compaction_switch false 'server2','server1'
+            hbase> compaction_switch false, 'server2','server1'
           NOTE: A server name is its host, port plus startcode. For example:
           host187.example.com,60020,1289493121758
         EOF