diff --git a/apps/openmw/mwworld/containerstore.cpp b/apps/openmw/mwworld/containerstore.cpp
index 6a0921013..52b311abb 100644
--- a/apps/openmw/mwworld/containerstore.cpp
+++ b/apps/openmw/mwworld/containerstore.cpp
@@ -585,7 +585,7 @@ float MWWorld::ContainerStore::getWeight() const
     return mCachedWeight;
 }
 
-int MWWorld::ContainerStore::getType (const Ptr& ptr)
+int MWWorld::ContainerStore::getType (const ConstPtr& ptr)
 {
     if (ptr.isEmpty())
         throw std::runtime_error ("can't put a non-existent object into a container");
diff --git a/apps/openmw/mwworld/containerstore.hpp b/apps/openmw/mwworld/containerstore.hpp
index b01a79366..e1e59d70f 100644
--- a/apps/openmw/mwworld/containerstore.hpp
+++ b/apps/openmw/mwworld/containerstore.hpp
@@ -163,7 +163,7 @@ namespace MWWorld
             float getWeight() const;
             ///< Return total weight of the items contained in *this.
 
-            static int getType (const Ptr& ptr);
+            static int getType (const ConstPtr& ptr);
             ///< This function throws an exception, if ptr does not point to an object, that can be
             /// put into a container.