diff --git a/src/engine/runtime.js b/src/engine/runtime.js
index 34c008a1e..2708ebe7e 100644
--- a/src/engine/runtime.js
+++ b/src/engine/runtime.js
@@ -104,6 +104,13 @@ class Runtime extends EventEmitter {
          */
         this._cloneCounter = 0;
 
+        /**
+         * Flag to emit a targets update at the end of a step. When target data
+         * changes, this flag is set to true.
+         * @type {boolean}
+         */
+        this._refreshTargets = false;
+
         /**
          * Whether the project is in "turbo mode."
          * @type {Boolean}
@@ -226,11 +233,11 @@ class Runtime extends EventEmitter {
     }
 
     /**
-     * Event name for sprite info report.
+     * Event name for targets update report.
      * @const {string}
      */
-    static get SPRITE_INFO_REPORT () {
-        return 'SPRITE_INFO_REPORT';
+    static get TARGETS_UPDATE () {
+        return 'TARGETS_UPDATE';
     }
 
     /**
@@ -638,6 +645,7 @@ class Runtime extends EventEmitter {
      * inactive threads after each iteration.
      */
     _step () {
+        this._refreshTargets = false;
         // Find all edge-activated hats, and add them to threads to be evaluated.
         for (const hatType in this._hats) {
             if (!this._hats.hasOwnProperty(hatType)) continue;
@@ -655,6 +663,7 @@ class Runtime extends EventEmitter {
             // @todo: Only render when this.redrawRequested or clones rendered.
             this.renderer.draw();
         }
+        if (this._refreshTargets) this.emit(Runtime.TARGETS_UPDATE);
     }
 
     /**
@@ -673,7 +682,7 @@ class Runtime extends EventEmitter {
         // Script glows must be cleared.
         this._scriptGlowsPreviousFrame = [];
         this._updateGlows();
-        this.spriteInfoReport(editingTarget);
+        this.requestTargetsUpdate(editingTarget);
     }
 
     /**
@@ -809,16 +818,6 @@ class Runtime extends EventEmitter {
         this.emit(Runtime.VISUAL_REPORT, {id: blockId, value: String(value)});
     }
 
-    /**
-     * Emit a sprite info report if the provided target is the original sprite
-     * @param {!Target} target Target to report sprite info for.
-     */
-    spriteInfoReport (target) {
-        if (!target.isOriginal) return;
-
-        this.emit(Runtime.SPRITE_INFO_REPORT, target.toJSON());
-    }
-
     /**
      * Get a target by its id.
      * @param {string} targetId Id of target to find.
@@ -896,6 +895,16 @@ class Runtime extends EventEmitter {
         this.redrawRequested = true;
     }
 
+    /**
+     * Emit a targets update at the end of the step if the provided target is
+     * the original sprite
+     * @param {!Target} target Target requesting the targets update
+     */
+    requestTargetsUpdate (target) {
+        if (!target.isOriginal) return;
+        this._refreshTargets = true;
+    }
+
     /**
      * Set up timers to repeatedly step in a browser.
      */
diff --git a/src/sprites/rendered-target.js b/src/sprites/rendered-target.js
index 1ffc00a1e..8489b37cb 100644
--- a/src/sprites/rendered-target.js
+++ b/src/sprites/rendered-target.js
@@ -197,7 +197,7 @@ class RenderedTarget extends Target {
             this.y = y;
         }
         this.emit(RenderedTarget.EVENT_TARGET_MOVED, this, oldX, oldY);
-        this.runtime.spriteInfoReport(this);
+        this.runtime.requestTargetsUpdate(this);
     }
 
     /**
@@ -240,7 +240,7 @@ class RenderedTarget extends Target {
                 this.runtime.requestRedraw();
             }
         }
-        this.runtime.spriteInfoReport(this);
+        this.runtime.requestTargetsUpdate(this);
     }
 
     /**
@@ -250,7 +250,7 @@ class RenderedTarget extends Target {
     setDraggable (draggable) {
         if (this.isStage) return;
         this.draggable = !!draggable;
-        this.runtime.spriteInfoReport(this);
+        this.runtime.requestTargetsUpdate(this);
     }
 
     /**
@@ -287,7 +287,7 @@ class RenderedTarget extends Target {
                 this.runtime.requestRedraw();
             }
         }
-        this.runtime.spriteInfoReport(this);
+        this.runtime.requestTargetsUpdate(this);
     }
 
     /**
@@ -386,7 +386,7 @@ class RenderedTarget extends Target {
                 this.runtime.requestRedraw();
             }
         }
-        this.runtime.spriteInfoReport(this);
+        this.runtime.requestTargetsUpdate(this);
     }
 
     /**
@@ -411,7 +411,7 @@ class RenderedTarget extends Target {
                 this.runtime.requestRedraw();
             }
         }
-        this.runtime.spriteInfoReport(this);
+        this.runtime.requestTargetsUpdate(this);
     }
 
     /**
@@ -483,7 +483,7 @@ class RenderedTarget extends Target {
                 this.runtime.requestRedraw();
             }
         }
-        this.runtime.spriteInfoReport(this);
+        this.runtime.requestTargetsUpdate(this);
     }
 
     /**
diff --git a/src/virtual-machine.js b/src/virtual-machine.js
index 719bf6cc7..79c16d2fc 100644
--- a/src/virtual-machine.js
+++ b/src/virtual-machine.js
@@ -19,42 +19,41 @@ class VirtualMachine extends EventEmitter {
     constructor () {
         super();
 
-        const instance = this;
         /**
          * VM runtime, to store blocks, I/O devices, sprites/targets, etc.
          * @type {!Runtime}
          */
-        instance.runtime = new Runtime();
+        this.runtime = new Runtime();
         /**
          * The "currently editing"/selected target ID for the VM.
          * Block events from any Blockly workspace are routed to this target.
          * @type {!string}
          */
-        instance.editingTarget = null;
+        this.editingTarget = null;
         // Runtime emits are passed along as VM emits.
-        instance.runtime.on(Runtime.SCRIPT_GLOW_ON, glowData => {
-            instance.emit(Runtime.SCRIPT_GLOW_ON, glowData);
+        this.runtime.on(Runtime.SCRIPT_GLOW_ON, glowData => {
+            this.emit(Runtime.SCRIPT_GLOW_ON, glowData);
         });
-        instance.runtime.on(Runtime.SCRIPT_GLOW_OFF, glowData => {
-            instance.emit(Runtime.SCRIPT_GLOW_OFF, glowData);
+        this.runtime.on(Runtime.SCRIPT_GLOW_OFF, glowData => {
+            this.emit(Runtime.SCRIPT_GLOW_OFF, glowData);
         });
-        instance.runtime.on(Runtime.BLOCK_GLOW_ON, glowData => {
-            instance.emit(Runtime.BLOCK_GLOW_ON, glowData);
+        this.runtime.on(Runtime.BLOCK_GLOW_ON, glowData => {
+            this.emit(Runtime.BLOCK_GLOW_ON, glowData);
         });
-        instance.runtime.on(Runtime.BLOCK_GLOW_OFF, glowData => {
-            instance.emit(Runtime.BLOCK_GLOW_OFF, glowData);
+        this.runtime.on(Runtime.BLOCK_GLOW_OFF, glowData => {
+            this.emit(Runtime.BLOCK_GLOW_OFF, glowData);
         });
-        instance.runtime.on(Runtime.PROJECT_RUN_START, () => {
-            instance.emit(Runtime.PROJECT_RUN_START);
+        this.runtime.on(Runtime.PROJECT_RUN_START, () => {
+            this.emit(Runtime.PROJECT_RUN_START);
         });
-        instance.runtime.on(Runtime.PROJECT_RUN_STOP, () => {
-            instance.emit(Runtime.PROJECT_RUN_STOP);
+        this.runtime.on(Runtime.PROJECT_RUN_STOP, () => {
+            this.emit(Runtime.PROJECT_RUN_STOP);
         });
-        instance.runtime.on(Runtime.VISUAL_REPORT, visualReport => {
-            instance.emit(Runtime.VISUAL_REPORT, visualReport);
+        this.runtime.on(Runtime.VISUAL_REPORT, visualReport => {
+            this.emit(Runtime.VISUAL_REPORT, visualReport);
         });
-        instance.runtime.on(Runtime.SPRITE_INFO_REPORT, spriteInfo => {
-            instance.emit(Runtime.SPRITE_INFO_REPORT, spriteInfo);
+        this.runtime.on(Runtime.TARGETS_UPDATE, () => {
+            this.emitTargetsUpdate();
         });
 
         this.blockListener = this.blockListener.bind(this);