diff --git a/projects/mtg/bin/Res/test/_tests.txt b/projects/mtg/bin/Res/test/_tests.txt
index 68fc41c15..6c7f3e37f 100644
--- a/projects/mtg/bin/Res/test/_tests.txt
+++ b/projects/mtg/bin/Res/test/_tests.txt
@@ -534,6 +534,7 @@ prowess_of_the_fair.txt
 prowess_of_the_fair2.txt
 prowess_of_the_fair3.txt
 PTInstant.txt
+PT_M15_errata.txt
 pygmy_troll.txt
 pyknite_i426.txt
 pyroclasm.txt
diff --git a/projects/mtg/include/AllAbilities.h b/projects/mtg/include/AllAbilities.h
index e8d099441..78df9b851 100644
--- a/projects/mtg/include/AllAbilities.h
+++ b/projects/mtg/include/AllAbilities.h
@@ -4307,10 +4307,10 @@ public:
     
     string newpower;
     bool newpowerfound;
-    int oldpower;
+    int oldpowerbonus;
     string newtoughness;
     bool newtoughnessfound;
-    int oldtoughness;
+    int oldtoughnessbonus;
     map<Damageable *, vector<MTGAbility *> > newAbilities;
     vector<string> newAbilitiesList;
     bool newAbilityFound;
diff --git a/projects/mtg/src/AllAbilities.cpp b/projects/mtg/src/AllAbilities.cpp
index e868654bb..429d51edd 100644
--- a/projects/mtg/src/AllAbilities.cpp
+++ b/projects/mtg/src/AllAbilities.cpp
@@ -4181,20 +4181,18 @@ for (it = types.begin(); it != types.end(); it++)
         }
     }
     if(newpowerfound )
-    {
+    {//setting p/t only overrides base p/t as of M15 changes
         WParsedInt * val = NEW WParsedInt(newpower,NULL, source);
-        oldpower = _target->power;
-        _target->power += val->getValue();
-        _target->power -= oldpower;
+        oldpowerbonus = _target->power - _target->origpower;//keep bonus if any
+        _target->setPower(oldpowerbonus + val->getValue());
         _target->power += reapplyCountersBonus(_target,false,true);
         delete val;
     }
     if(newtoughnessfound )
-    {
+    {//setting p/t only overrides base p/t as of M15 changes
         WParsedInt * val = NEW WParsedInt(newtoughness,NULL, source);
-        oldtoughness = _target->toughness;
-        _target->addToToughness(val->getValue());
-        _target->addToToughness(-oldtoughness);
+        oldtoughnessbonus = _target->toughness - _target->origtoughness;// keep bonus if any
+        _target->setToughness(oldtoughnessbonus + val->getValue());
         _target->addToToughness(reapplyCountersBonus(_target,true,false));
         _target->life = _target->toughness;
         delete val;
@@ -4283,11 +4281,11 @@ int ATransformer::destroy()
 
         if(newpowerfound )
         {
-            _target->power = oldpower;
+            _target->setPower(oldpowerbonus + _target->origpower);
         }
         if(newtoughnessfound )
         {
-            _target->setToughness(oldtoughness);
+            _target->setToughness(oldtoughnessbonus + _target->origtoughness);
         }
         if(newAbilityFound)
         {