diff --git a/apps/opencs/model/world/data.cpp b/apps/opencs/model/world/data.cpp
index ecb230f58c..856b00e909 100644
--- a/apps/opencs/model/world/data.cpp
+++ b/apps/opencs/model/world/data.cpp
@@ -130,7 +130,7 @@ int CSMWorld::Data::count (RecordBase::State state, const CollectionBase& collec
 }
 
 CSMWorld::Data::Data (ToUTF8::FromType encoding, const ResourcesManager& resourcesManager)
-: mEncoder (encoding), mPathgrids (mCells), mRefs (mCells), mReferenceables(self()),
+: mEncoder (encoding), mPathgrids (mCells), mReferenceables(self()), mRefs (mCells),
   mResourcesManager (resourcesManager), mReader (0), mDialogue (0), mReaderIndex(0)
 {
     int index = 0;
@@ -1526,7 +1526,7 @@ CSMWorld::NpcStats* CSMWorld::Data::npcAutoCalculate(const ESM::NPC& npc) const
     if (autoCalc)
         level = npc.mNpdt12.mLevel;
 
-    CSMWorld::NpcStats *stats = new CSMWorld::NpcStats();
+    std::auto_ptr<CSMWorld::NpcStats> stats (new CSMWorld::NpcStats());
 
     CSStore store(mGmsts, mSkills, mMagicEffects, mSpells);
 
@@ -1547,7 +1547,7 @@ CSMWorld::NpcStats* CSMWorld::Data::npcAutoCalculate(const ESM::NPC& npc) const
         for (std::vector<std::string>::const_iterator it = npc.mSpells.mList.begin();
                 it != npc.mSpells.mList.end(); ++it)
         {
-            stats->addSpells(*it);
+            stats->addSpell(*it);
         }
     }
 
@@ -1605,8 +1605,11 @@ CSMWorld::NpcStats* CSMWorld::Data::npcAutoCalculate(const ESM::NPC& npc) const
         }
     }
 
-    emit cacheNpcStats (npc.mId, stats);
-    return stats;
+    if (stats.get() == 0)
+        return 0;
+
+    emit cacheNpcStats (npc.mId, stats.release());
+    return stats.release();
 }
 
 void CSMWorld::Data::cacheNpcStatsEvent (const std::string& id, CSMWorld::NpcStats *stats)
diff --git a/apps/opencs/model/world/npcstats.cpp b/apps/opencs/model/world/npcstats.cpp
index da14b473e1..5b84849348 100644
--- a/apps/opencs/model/world/npcstats.cpp
+++ b/apps/opencs/model/world/npcstats.cpp
@@ -45,7 +45,7 @@ namespace CSMWorld
         mAttr[index] = value;
     }
 
-    void NpcStats::addSpells(std::string id)
+    void NpcStats::addSpell(const std::string& id)
     {
         struct SpellInfo info;
         info.mName = id;
diff --git a/apps/opencs/model/world/npcstats.hpp b/apps/opencs/model/world/npcstats.hpp
index 4d9be149fb..8cefe586fc 100644
--- a/apps/opencs/model/world/npcstats.hpp
+++ b/apps/opencs/model/world/npcstats.hpp
@@ -43,7 +43,7 @@ namespace CSMWorld
 
         virtual void setAttribute(int index, unsigned char value);
 
-        virtual void addSpells(std::string id);
+        virtual void addSpell(const std::string& id);
 
         void addPowers(const std::string& id, int type);
 
diff --git a/apps/openmw/mwclass/npc.cpp b/apps/openmw/mwclass/npc.cpp
index 64ed868a13..3b0234a252 100644
--- a/apps/openmw/mwclass/npc.cpp
+++ b/apps/openmw/mwclass/npc.cpp
@@ -74,7 +74,7 @@ namespace
 
         virtual void setAttribute(int index, unsigned char value) { mNpcStats.setAttribute(index, value); }
 
-        virtual void addSpells(std::string id) { mNpcStats.getSpells().add(id); }
+        virtual void addSpell(const std::string& id) { mNpcStats.getSpells().add(id); }
 
         virtual unsigned char getBaseSkill(int index) const { return mNpcStats.getSkill(index).getBase(); }
 
diff --git a/components/autocalc/autocalc.cpp b/components/autocalc/autocalc.cpp
index 78cd549ca4..122d19763e 100644
--- a/components/autocalc/autocalc.cpp
+++ b/components/autocalc/autocalc.cpp
@@ -11,7 +11,6 @@
 
 #include "autocalcspell.hpp"
 
-// Most of the code in this file was moved from apps/openmw/mwclass/npc.cpp
 namespace
 {
     int is_even(double d)
@@ -117,7 +116,7 @@ namespace AutoCalc
                 int index = class_->mData.mSkills[i2][i];
                 if (index >= 0 && index < ESM::Skill::Length)
                 {
-                    stats.setBaseSkill (index, stats.getBaseSkill(index) + bonus);
+                    stats.setBaseSkill (index, bonus);
                 }
             }
         }
@@ -168,7 +167,7 @@ namespace AutoCalc
         }
     }
 
-    unsigned short autoCalculateHealth(int level, const ESM::Class *class_, StatsBase& stats)
+    unsigned short autoCalculateHealth(int level, const ESM::Class *class_, const StatsBase& stats)
     {
         // initial health
         int strength = stats.getBaseAttribute(ESM::Attribute::Strength);
@@ -200,7 +199,7 @@ namespace AutoCalc
 
         std::vector<std::string> spells = autoCalcNpcSpells(skills, attributes, race, store);
         for (std::vector<std::string>::iterator it = spells.begin(); it != spells.end(); ++it)
-            stats.addSpells(*it);
+            stats.addSpell(*it);
     }
 
     StatsBase::StatsBase() {}
diff --git a/components/autocalc/autocalc.hpp b/components/autocalc/autocalc.hpp
index 3f4b6bae16..5cfe06b426 100644
--- a/components/autocalc/autocalc.hpp
+++ b/components/autocalc/autocalc.hpp
@@ -27,7 +27,7 @@ namespace AutoCalc
 
         virtual void setAttribute(int index, unsigned char value) = 0;
 
-        virtual void addSpells(std::string id) = 0;
+        virtual void addSpell(const std::string& id) = 0;
 
         virtual unsigned char getBaseSkill(int index) const = 0;
 
@@ -40,7 +40,7 @@ namespace AutoCalc
     void autoCalcSkillsImpl (const ESM::NPC* npc,
             const ESM::Race *race, const ESM::Class *class_, int level, StatsBase& stats, StoreCommon *store);
 
-    unsigned short autoCalculateHealth(int level, const ESM::Class *class_, StatsBase& stats);
+    unsigned short autoCalculateHealth(int level, const ESM::Class *class_, const StatsBase& stats);
 
     void autoCalculateSpells(const ESM::Race *race, StatsBase& stats, StoreCommon *store);
 }
diff --git a/components/autocalc/autocalcspell.cpp b/components/autocalc/autocalcspell.cpp
index 01c25a6952..78499a0927 100644
--- a/components/autocalc/autocalcspell.cpp
+++ b/components/autocalc/autocalcspell.cpp
@@ -13,7 +13,6 @@
 
 #include "autocalc.hpp"
 
-// Most of the code in this file was moved from apps/openmw/mwmechanics/autocalcspell.cpp
 namespace AutoCalc
 {
 
diff --git a/components/autocalc/store.hpp b/components/autocalc/store.hpp
index 67061eef9c..9a798a5ce8 100644
--- a/components/autocalc/store.hpp
+++ b/components/autocalc/store.hpp
@@ -4,15 +4,8 @@
 #include <vector>
 #include <string>
 
-namespace Loading
-{
-    class Listener;
-}
-
 namespace ESM
 {
-    class ESMWriter;
-    class ESMReader;
     struct Spell;
     struct Skill;
     struct MagicEffect;