diff --git a/doomsday/libdeng2/include/de/core/asset.h b/doomsday/libdeng2/include/de/core/asset.h
index 14be2845b9..6f161270e5 100644
--- a/doomsday/libdeng2/include/de/core/asset.h
+++ b/doomsday/libdeng2/include/de/core/asset.h
@@ -114,6 +114,11 @@ class DENG2_PUBLIC AssetGroup : public Asset,
         return *this;
     }
 
+    AssetGroup &operator -= (Asset const &dep) {
+        remove(dep);
+        return *this;
+    }
+
     bool has(Asset const &dep) const;
 
     void setPolicy(Asset const &asset, Policy policy);
diff --git a/doomsday/libdeng2/src/core/asset.cpp b/doomsday/libdeng2/src/core/asset.cpp
index ca9eda0fd6..70e1469111 100644
--- a/doomsday/libdeng2/src/core/asset.cpp
+++ b/doomsday/libdeng2/src/core/asset.cpp
@@ -110,6 +110,7 @@ void AssetGroup::clear()
     DENG2_FOR_EACH(Members, i, d->deps)
     {
         i->first->audienceForDeletion -= this;
+        i->first->audienceForStateChange -= this;
     }
 
     d->deps.clear();
@@ -120,12 +121,14 @@ void AssetGroup::insert(Asset const &asset, Policy policy)
 {
     d->deps[&asset] = policy;
     asset.audienceForDeletion += this;
+    asset.audienceForStateChange += this;
     d->update(*this);
 }
 
 void AssetGroup::remove(Asset const &asset)
 {
     asset.audienceForDeletion -= this;
+    asset.audienceForStateChange -= this;
     d->deps.erase(&asset);
     d->update(*this);
 }
@@ -150,7 +153,10 @@ AssetGroup::Members const &AssetGroup::all() const
 
 void AssetGroup::assetDeleted(Asset &asset)
 {
-    remove(asset);
+    if(has(asset))
+    {
+        remove(asset);
+    }
 }
 
 void AssetGroup::assetStateChanged(Asset &)