--- a/devtools/client/webconsole/new-console-output/store.js
+++ b/devtools/client/webconsole/new-console-output/store.js
@@ -13,16 +13,17 @@ const {
 } = require("devtools/client/shared/vendor/redux");
 const { thunk } = require("devtools/client/shared/redux/middleware/thunk");
 const {
   BATCH_ACTIONS
 } = require("devtools/client/shared/redux/middleware/debounce");
 const {
   MESSAGE_ADD,
   MESSAGE_OPEN,
+  MESSAGES_ADD,
   MESSAGES_CLEAR,
   REMOVED_ACTORS_CLEAR,
   NETWORK_MESSAGE_UPDATE,
   PREFS,
 } = require("devtools/client/webconsole/new-console-output/constants");
 const { reducers } = require("./reducers/index");
 const Services = require("Services");
 const {
@@ -127,17 +128,17 @@ function enableBatching() {
  */
 function enableActorReleaser(hud) {
   return next => (reducer, initialState, enhancer) => {
     function releaseActorsEnhancer(state, action) {
       state = reducer(state, action);
 
       let type = action.type;
       let proxy = hud ? hud.proxy : null;
-      if (proxy && (type == MESSAGE_ADD || type == MESSAGES_CLEAR)) {
+      if (proxy && ([MESSAGE_ADD, MESSAGES_ADD, MESSAGES_CLEAR].includes(type))) {
         releaseActors(state.messages.removedActors, proxy);
 
         // Reset `removedActors` in message reducer.
         state = reducer(state, {
           type: REMOVED_ACTORS_CLEAR
         });
       }
 

--- a/devtools/client/webconsole/new-console-output/test/helpers.js
+++ b/devtools/client/webconsole/new-console-output/test/helpers.js
@@ -18,24 +18,21 @@ const {
 } = require("devtools/client/webconsole/new-console-output/selectors/messages");
 
 /**
  * Prepare actions for use in testing.
  */
 function setupActions() {
   // Some actions use dependency injection. This helps them avoid using state in
   // a hard-to-test way. We need to inject stubbed versions of these dependencies.
-  const wrappedActions = Object.assign({}, actions);
-
   const idGenerator = new IdGenerator();
-  wrappedActions.messageAdd = (packet) => {
-    return actions.messageAdd(packet, idGenerator);
-  };
-
-  return wrappedActions;
+  return Object.assign({}, actions, {
+    messageAdd: packet => actions.messageAdd(packet, idGenerator),
+    messagesAdd: packets => actions.messagesAdd(packets, idGenerator)
+  });
 }
 
 /**
  * Prepare the store for use in testing.
  */
 function setupStore(input = [], hud, options) {
   const store = configureStore(hud, options);
 

--- a/devtools/client/webconsole/new-console-output/test/store/release-actors.test.js
+++ b/devtools/client/webconsole/new-console-output/test/store/release-actors.test.js
@@ -18,17 +18,17 @@ const expect = require("expect");
 describe("Release actor enhancer:", () => {
   let actions;
 
   before(() => {
     actions = setupActions();
   });
 
   describe("Client proxy", () => {
-    it("properly releases backend actors when limit is reached", () => {
+    it("releases backend actors when limit reached adding a single message", () => {
       const logLimit = 100;
       let releasedActors = [];
       const { dispatch, getState } = setupStore([], {
         proxy: {
           releaseActor: (actor) => {
             releasedActors.push(actor);
           }
         }
@@ -58,16 +58,64 @@ describe("Release actor enhancer:", () =
       }
 
       expect(releasedActors.length).toBe(3);
       expect(releasedActors).toInclude(firstMessageActor);
       expect(releasedActors).toInclude(secondMessageActor);
       expect(releasedActors).toInclude(thirdMessageActor);
     });
 
+    it("releases backend actors when limit reached adding multiple messages", () => {
+      const logLimit = 100;
+      let releasedActors = [];
+      const { dispatch, getState } = setupStore([], {
+        proxy: {
+          releaseActor: (actor) => {
+            releasedActors.push(actor);
+          }
+        }
+      }, { logLimit });
+
+      // Add a log message.
+      dispatch(actions.messageAdd(
+        stubPackets.get("console.log('myarray', ['red', 'green', 'blue'])")));
+
+      let messages = getAllMessagesById(getState());
+      const firstMessage = messages.first();
+      const firstMessageActor = firstMessage.parameters[1].actor;
+
+      // Add an evaluation result message (see Bug 1408321).
+      const evaluationResultPacket = stubPackets.get("new Date(0)");
+      dispatch(actions.messageAdd(evaluationResultPacket));
+      const secondMessageActor = evaluationResultPacket.result.actor;
+
+      // Add an assertion message.
+      const assertPacket = stubPackets.get("console.assert(false, {message: 'foobar'})");
+      dispatch(actions.messageAdd(assertPacket));
+      const thirdMessageActor = assertPacket.message.arguments[0].actor;
+
+      // Add ${logLimit} messages so we prune the ones we added before.
+      const packets = [];
+      // Alternate between 2 packets so we don't trigger the repeat message mechanism.
+      const oddPacket = stubPackets.get("console.log(undefined)");
+      const evenPacket = stubPackets.get("console.log('foobar', 'test')");
+      for (let i = 0; i < logLimit; i++) {
+        const packet = i % 2 === 0 ? evenPacket : oddPacket;
+        packets.push(packet);
+      }
+
+      // Add all the packets at once. This will prune the first 3 messages.
+      dispatch(actions.messagesAdd(packets));
+
+      expect(releasedActors.length).toBe(3);
+      expect(releasedActors).toInclude(firstMessageActor);
+      expect(releasedActors).toInclude(secondMessageActor);
+      expect(releasedActors).toInclude(thirdMessageActor);
+    });
+
     it("properly releases backend actors after clear", () => {
       let releasedActors = [];
       const { dispatch, getState } = setupStore([], {
         proxy: {
           releaseActor: (actor) => {
             releasedActors.push(actor);
           }
         }