diff --git a/atlas-lwcapi/src/main/scala/com/netflix/atlas/lwcapi/SubscriptionManager.scala b/atlas-lwcapi/src/main/scala/com/netflix/atlas/lwcapi/SubscriptionManager.scala
index 8a4d60f2b..cf45bc957 100644
--- a/atlas-lwcapi/src/main/scala/com/netflix/atlas/lwcapi/SubscriptionManager.scala
+++ b/atlas-lwcapi/src/main/scala/com/netflix/atlas/lwcapi/SubscriptionManager.scala
@@ -44,6 +44,7 @@ class SubscriptionManager[T](registry: Registry) extends StrictLogging {
 
   private val subHandlers = new ConcurrentHashMap[String, ConcurrentSet[T]]()
 
+  @volatile private var subscriptionsList = List.empty[Subscription]
   @volatile private var queryIndex = QueryIndex.create[Subscription](Nil)
   @volatile private var queryListChanged = false
 
@@ -57,7 +58,13 @@ class SubscriptionManager[T](registry: Registry) extends StrictLogging {
   private[lwcapi] def regenerateQueryIndex(): Unit = {
     if (queryListChanged) {
       queryListChanged = false
-      val entries = subscriptions.map { sub =>
+      subscriptionsList = registrations
+        .values()
+        .asScala
+        .flatMap(_.subscriptions)
+        .toList
+        .distinct
+      val entries = subscriptionsList.map { sub =>
         QueryIndex.Entry(sub.query, sub)
       }
       queryIndex = QueryIndex.create(entries)
@@ -219,12 +226,7 @@ class SubscriptionManager[T](registry: Registry) extends StrictLogging {
     * Return the set of all current subscriptions across all streams.
     */
   def subscriptions: List[Subscription] = {
-    registrations
-      .values()
-      .asScala
-      .flatMap(_.subscriptions)
-      .toList
-      .distinct
+    subscriptionsList
   }
 
   /**
diff --git a/atlas-lwcapi/src/test/scala/com/netflix/atlas/lwcapi/SubscriptionManagerSuite.scala b/atlas-lwcapi/src/test/scala/com/netflix/atlas/lwcapi/SubscriptionManagerSuite.scala
index 723d3f88e..7d0db5bef 100644
--- a/atlas-lwcapi/src/test/scala/com/netflix/atlas/lwcapi/SubscriptionManagerSuite.scala
+++ b/atlas-lwcapi/src/test/scala/com/netflix/atlas/lwcapi/SubscriptionManagerSuite.scala
@@ -73,9 +73,11 @@ class SubscriptionManagerSuite extends FunSuite {
 
     val exp1 = sub("name,exp1,:eq")
     sm.subscribe(meta.streamId, exp1)
+    sm.regenerateQueryIndex()
     assertEquals(sm.subscriptions, List(exp1))
 
     assert(!sm.register(meta, 1))
+    sm.regenerateQueryIndex()
     assertEquals(sm.subscriptions, List(exp1))
   }
 
@@ -86,6 +88,7 @@ class SubscriptionManagerSuite extends FunSuite {
 
     val subs = List(sub("name,exp1,:eq"), sub("name,exp2,:eq"))
     sm.subscribe(meta.streamId, subs)
+    sm.regenerateQueryIndex()
 
     assertEquals(sm.subscriptions.toSet, subs.toSet)
   }
@@ -98,6 +101,7 @@ class SubscriptionManagerSuite extends FunSuite {
     val s = sub("name,exp1,:eq")
     sm.subscribe(meta.streamId, s)
     sm.subscribe(meta.streamId, s)
+    sm.regenerateQueryIndex()
 
     assertEquals(sm.subscriptions, List(s))
   }
@@ -112,6 +116,7 @@ class SubscriptionManagerSuite extends FunSuite {
     val s = sub("name,exp1,:eq")
     sm.subscribe(a.streamId, s)
     sm.subscribe(b.streamId, s)
+    sm.regenerateQueryIndex()
 
     assertEquals(sm.subscriptions, List(s))
     assertEquals(sm.subscriptionsForStream(a.streamId), List(s))