diff --git a/src/engine/runtime.js b/src/engine/runtime.js
index e94667015..532a35388 100644
--- a/src/engine/runtime.js
+++ b/src/engine/runtime.js
@@ -1770,7 +1770,7 @@ class Runtime extends EventEmitter {
         }
 
         if (this._refreshTargets) {
-            this.emit(Runtime.TARGETS_UPDATE);
+            this.emit(Runtime.TARGETS_UPDATE, false /* Don't emit project changed */);
             this._refreshTargets = false;
         }
 
diff --git a/src/virtual-machine.js b/src/virtual-machine.js
index 38eb79e9f..0db45536b 100644
--- a/src/virtual-machine.js
+++ b/src/virtual-machine.js
@@ -94,8 +94,8 @@ class VirtualMachine extends EventEmitter {
         this.runtime.on(Runtime.VISUAL_REPORT, visualReport => {
             this.emit(Runtime.VISUAL_REPORT, visualReport);
         });
-        this.runtime.on(Runtime.TARGETS_UPDATE, () => {
-            this.emitTargetsUpdate();
+        this.runtime.on(Runtime.TARGETS_UPDATE, emitProjectChanged => {
+            this.emitTargetsUpdate(emitProjectChanged);
         });
         this.runtime.on(Runtime.MONITORS_UPDATE, monitorList => {
             this.emit(Runtime.MONITORS_UPDATE, monitorList);
@@ -201,7 +201,7 @@ class VirtualMachine extends EventEmitter {
     clear () {
         this.runtime.dispose();
         this.editingTarget = null;
-        this.emitTargetsUpdate();
+        this.emitTargetsUpdate(false /* Don't emit project change */);
     }
 
     /**
@@ -562,10 +562,12 @@ class VirtualMachine extends EventEmitter {
             .then(validatedInput => {
                 const projectVersion = validatedInput[0].projectVersion;
                 if (projectVersion === 2) {
-                    return this._addSprite2(validatedInput[0], validatedInput[1]);
+                    return this._addSprite2(validatedInput[0], validatedInput[1])
+                        .then(() => this.runtime.emitProjectChanged());
                 }
                 if (projectVersion === 3) {
-                    return this._addSprite3(validatedInput[0], validatedInput[1]);
+                    return this._addSprite3(validatedInput[0], validatedInput[1])
+                        .then(() => this.runtime.emitProjectChanged());
                 }
                 return Promise.reject(`${errorPrefix} Unable to verify sprite version.`);
             })
@@ -627,6 +629,7 @@ class VirtualMachine extends EventEmitter {
                 target.setCostume(
                     target.getCostumes().length - 1
                 );
+                this.runtime.emitProjectChanged();
             });
         }
         // If the target cannot be found by id, return a rejected promise
@@ -698,6 +701,7 @@ class VirtualMachine extends EventEmitter {
         const deletedCostume = this.editingTarget.deleteCostume(costumeIndex);
         if (deletedCostume) {
             const target = this.editingTarget;
+            this.runtime.emitProjectChanged();
             return () => {
                 target.addCostume(deletedCostume);
                 this.emitTargetsUpdate();
@@ -797,6 +801,7 @@ class VirtualMachine extends EventEmitter {
         const target = this.editingTarget;
         const deletedSound = this.editingTarget.deleteSound(soundIndex);
         if (deletedSound) {
+            this.runtime.emitProjectChanged();
             const restoreFun = () => {
                 target.addSound(deletedSound);
                 this.emitTargetsUpdate();
@@ -928,6 +933,7 @@ class VirtualMachine extends EventEmitter {
             const stage = this.runtime.getTargetForStage();
             stage.addCostume(backdropObject);
             stage.setCostume(stage.getCostumes().length - 1);
+            this.runtime.emitProjectChanged();
         });
     }
 
@@ -958,8 +964,9 @@ class VirtualMachine extends EventEmitter {
                     const currTarget = allTargets[i];
                     currTarget.blocks.updateAssetName(oldName, newName, 'sprite');
                 }
+
+                if (newUnusedName !== oldName) this.emitTargetsUpdate();
             }
-            this.emitTargetsUpdate();
         } else {
             throw new Error('No target with the provided id.');
         }
@@ -1281,7 +1288,9 @@ class VirtualMachine extends EventEmitter {
             // Currently editing target id.
             editingTarget: this.editingTarget ? this.editingTarget.id : null
         });
-        if (triggerProjectChange) this.runtime.emitProjectChanged();
+        if (triggerProjectChange) {
+            this.runtime.emitProjectChanged();
+        }
     }
 
     /**
@@ -1383,7 +1392,11 @@ class VirtualMachine extends EventEmitter {
     reorderCostume (targetId, costumeIndex, newIndex) {
         const target = this.runtime.getTargetById(targetId);
         if (target) {
-            return target.reorderCostume(costumeIndex, newIndex);
+            const reorderSuccessful = target.reorderCostume(costumeIndex, newIndex);
+            if (reorderSuccessful) {
+                this.runtime.emitProjectChanged();
+            }
+            return reorderSuccessful;
         }
         return false;
     }
@@ -1398,7 +1411,11 @@ class VirtualMachine extends EventEmitter {
     reorderSound (targetId, soundIndex, newIndex) {
         const target = this.runtime.getTargetById(targetId);
         if (target) {
-            return target.reorderSound(soundIndex, newIndex);
+            const reorderSuccessful = target.reorderSound(soundIndex, newIndex);
+            if (reorderSuccessful) {
+                this.runtime.emitProjectChanged();
+            }
+            return reorderSuccessful;
         }
         return false;
     }
@@ -1440,6 +1457,11 @@ class VirtualMachine extends EventEmitter {
         } else {
             this.editingTarget.postSpriteInfo(data);
         }
+        // Post sprite info means the gui has changed something about a sprite,
+        // either through the sprite info pane fields (e.g. direction, size) or
+        // through dragging a sprite on the stage
+        // Emit a project changed event.
+        this.runtime.emitProjectChanged();
     }
 
     /**