diff --git a/src/blocks/scratch3_event.js b/src/blocks/scratch3_event.js
index 10ceb10cc3..1e50b4b981 100644
--- a/src/blocks/scratch3_event.js
+++ b/src/blocks/scratch3_event.js
@@ -83,9 +83,7 @@ class Scratch3EventBlocks {
             args.BROADCAST_OPTION.id, args.BROADCAST_OPTION.name);
         if (broadcastVar) {
             const broadcastOption = broadcastVar.name;
-            util.startHats('event_whenbroadcastreceived', {
-                BROADCAST_OPTION: broadcastOption
-            });
+            this._broadcast(broadcastOption, util);
         }
     }
 
@@ -99,11 +97,7 @@ class Scratch3EventBlocks {
             // Have we run before, starting threads?
             if (!util.stackFrame.startedThreads) {
                 // No - start hats for this broadcast.
-                util.stackFrame.startedThreads = util.startHats(
-                    'event_whenbroadcastreceived', {
-                        BROADCAST_OPTION: broadcastOption
-                    }
-                );
+                util.stackFrame.startedThreads = this._broadcast(broadcastOption, util);
                 if (util.stackFrame.startedThreads.length === 0) {
                     // Nothing was started.
                     return;
@@ -132,6 +126,14 @@ class Scratch3EventBlocks {
             }
         }
     }
+
+    _broadcast (broadcastOption, util) { // used by compiler
+        const threads = util.startHats('event_whenbroadcastreceived', {
+            BROADCAST_OPTION: broadcastOption
+        });
+        this.runtime.emit('BROADCAST_SENT', broadcastOption);
+        return threads;
+    }
 }
 
 module.exports = Scratch3EventBlocks;
diff --git a/src/compiler/jsgen.js b/src/compiler/jsgen.js
index ff07f3f0d5..4b8c180f17 100644
--- a/src/compiler/jsgen.js
+++ b/src/compiler/jsgen.js
@@ -910,11 +910,11 @@ class JSGenerator {
             break;
 
         case 'event.broadcast':
-            this.source += `startHats("event_whenbroadcastreceived", { BROADCAST_OPTION: ${this.descendInput(node.broadcast).asString()} });\n`;
+            this.source += `runtime.ext_scratch3_event._broadcast(${this.descendInput(node.broadcast).asString()}, {startHats});\n`;
             this.resetVariableInputs();
             break;
         case 'event.broadcastAndWait':
-            this.source += `yield* waitThreads(startHats("event_whenbroadcastreceived", { BROADCAST_OPTION: ${this.descendInput(node.broadcast).asString()} }));\n`;
+            this.source += `yield* waitThreads(runtime.ext_scratch3_event._broadcast(${this.descendInput(node.broadcast).asString()}, {startHats}));\n`;
             this.yielded();
             break;