diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/UnassignProcedure.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/UnassignProcedure.java
index 740c7ff8824..c6b7e4b1180 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/UnassignProcedure.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/UnassignProcedure.java
@@ -161,9 +161,12 @@ public class UnassignProcedure extends RegionTransitionProcedure {
       return false;
     }
 
-    // if the server is down, mark the operation as complete
+    // if the server is down, mark the operation as failed. region cannot be unassigned
+    // if server is down
     if (serverCrashed.get() || !isServerOnline(env, regionNode)) {
-      LOG.info("Server already down: " + this + "; " + regionNode.toShortString());
+      LOG.warn("Server already down: " + this + "; " + regionNode.toShortString());
+      setFailure("source region server not online",
+          new ServerCrashException(getProcId(), regionNode.getRegionLocation()));
       return false;
     }
 
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/master/procedure/TestServerCrashProcedure.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/procedure/TestServerCrashProcedure.java
index 0a31a84b33d..9d6e765c224 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/master/procedure/TestServerCrashProcedure.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/procedure/TestServerCrashProcedure.java
@@ -87,7 +87,6 @@ public class TestServerCrashProcedure {
     testRecoveryAndDoubleExecution(false, false);
   }
 
-  @Ignore  // HBASE-18366... To be enabled again.
   @Test(timeout=60000)
   public void testRecoveryAndDoubleExecutionOnRsWithMeta() throws Exception {
     testRecoveryAndDoubleExecution(true, true);