diff --git a/core/src/main/java/org/elasticsearch/rest/action/cat/AbstractCatAction.java b/core/src/main/java/org/elasticsearch/rest/action/cat/AbstractCatAction.java
index 86739046eb9..7289e9c76e7 100644
--- a/core/src/main/java/org/elasticsearch/rest/action/cat/AbstractCatAction.java
+++ b/core/src/main/java/org/elasticsearch/rest/action/cat/AbstractCatAction.java
@@ -76,7 +76,7 @@ public abstract class AbstractCatAction extends BaseRestHandler {
     }
 
     static Set<String> RESPONSE_PARAMS =
-            Collections.unmodifiableSet(new HashSet<>(Arrays.asList("format", "h", "v", "ts", "pri", "bytes", "size", "time")));
+            Collections.unmodifiableSet(new HashSet<>(Arrays.asList("format", "h", "v", "ts", "pri", "bytes", "size", "time", "s")));
 
     @Override
     protected Set<String> responseParams() {