diff --git a/components/esm/loadnpc.hpp b/components/esm/loadnpc.hpp
index ff255608fa..31104a71fb 100644
--- a/components/esm/loadnpc.hpp
+++ b/components/esm/loadnpc.hpp
@@ -80,7 +80,8 @@ struct NPC
              mPersonality,
              mLuck;
 
-        char mSkills[Skill::Length];
+        // mSkill vals are used only in MWMechanics::AttributeValue.setBase(), if less than 0 they are not considered
+        unsigned char mSkills[Skill::Length];
 
         // at opencs/model/tools/referenceablecheck.cpp:679 is assumed that negative reputation values are invalid, can we assume we won't find any negative value?
         unsigned char mReputation;
diff --git a/components/esm/loadregn.hpp b/components/esm/loadregn.hpp
index 1992c951b4..c231b6aa0d 100644
--- a/components/esm/loadregn.hpp
+++ b/components/esm/loadregn.hpp
@@ -24,10 +24,11 @@ struct Region
 #pragma pack(1)
     struct WEATstruct
     {
-        // I guess these are probabilities
-        char mClear, mCloudy, mFoggy, mOvercast, mRain, mThunder, mAsh, mBlight,
+        // These are probabilities that add up to 100
+        unsigned char mClear, mCloudy, mFoggy, mOvercast, mRain, mThunder, mAsh, mBlight,
         // Unknown weather, probably snow and something. Only
         // present in file version 1.3.
+        // the engine uses mA as "snow" and mB as "blizard"
                 mA, mB;
     }; // 10 bytes
 
@@ -35,7 +36,7 @@ struct Region
     struct SoundRef
     {
         NAME32 mSound;
-        char mChance;
+        unsigned char mChance;
     }; // 33 bytes
 #pragma pack(pop)