diff --git a/external/opensearch/src/main/java/org/apache/stormcrawler/opensearch/persistence/AbstractSpout.java b/external/opensearch/src/main/java/org/apache/stormcrawler/opensearch/persistence/AbstractSpout.java
index 43b0e4289..21ba324fb 100644
--- a/external/opensearch/src/main/java/org/apache/stormcrawler/opensearch/persistence/AbstractSpout.java
+++ b/external/opensearch/src/main/java/org/apache/stormcrawler/opensearch/persistence/AbstractSpout.java
@@ -225,11 +225,14 @@ public void fail(Object msgId) {
 
     @Override
     public void close() {
-        if (client != null) {
-            try {
-                client.close();
-            } catch (IOException e) {
-                LOG.error("Exception caught when closing client", e);
+        synchronized (AbstractSpout.class) {
+            if (client != null) {
+                try {
+                    client.close();
+                } catch (IOException e) {
+                    LOG.error("Exception caught when closing client", e);
+                }
+                client = null;
             }
         }
     }