diff --git a/PKHeX/MainWindow/Main.cs b/PKHeX/MainWindow/Main.cs
index 4071e375d..b969a6449 100644
--- a/PKHeX/MainWindow/Main.cs
+++ b/PKHeX/MainWindow/Main.cs
@@ -1228,6 +1228,8 @@ private void setAbilityList()
                 formnum = CB_Form.SelectedIndex;
 
             int[] abils = SAV.Personal.getAbilities(species, formnum);
+            if (abils[1] == 0)
+                abils[1] = abils[0];
             string[] abilIdentifier = {" (1)", " (2)", " (H)"};
             List<string> ability_list = abils.Where(a => a != 0).Select((t, i) => abilitylist[t] + abilIdentifier[i]).ToList();
             if (!ability_list.Any())
@@ -1652,6 +1654,9 @@ private void updateRandomPID(object sender, EventArgs e)
                 pkm.setPIDNature(Util.getIndex(CB_Nature));
             else if (sender == BTN_RerollPID)
                 pkm.setPIDGender(pkm.Gender);
+            else if (sender == CB_Ability && CB_Ability.SelectedIndex != pkm.PIDAbility && pkm.PIDAbility > -1)
+                pkm.PID = PKX.getRandomPID(pkm.Species, pkm.Gender, pkm.Version, pkm.Nature, pkm.Format, (uint)(CB_Ability.SelectedIndex * 0x10001));
+
             TB_PID.Text = pkm.PID.ToString("X8");
             getQuickFiller(dragout);
             if (pkm.GenNumber < 6 && TB_EC.Visible)
@@ -2203,10 +2208,15 @@ private void validateComboBox2(object sender, EventArgs e)
             if (!fieldsInitialized)
                 return;
             validateComboBox(sender, e);
-            if (sender == CB_Ability)
-                TB_AbilityNumber.Text = (1 << CB_Ability.SelectedIndex).ToString();
-            if (fieldsLoaded && sender == CB_Nature && SAV.Generation <= 4)
-                updateRandomPID(sender, e);
+            if (fieldsLoaded)
+            {
+                if (sender == CB_Ability && SAV.Generation >= 6)
+                    TB_AbilityNumber.Text = (1 << CB_Ability.SelectedIndex).ToString();
+                if (sender == CB_Ability && SAV.Generation <= 5 && CB_Ability.SelectedIndex < 2) // not hidden
+                    updateRandomPID(sender, e);
+                if (sender == CB_Nature && SAV.Generation <= 4)
+                    updateRandomPID(sender, e);
+            }
             updateNatureModification(sender, null);
             updateIVs(null, null); // updating Nature will trigger stats to update as well
         }
diff --git a/PKHeX/MainWindow/MainPK4.cs b/PKHeX/MainWindow/MainPK4.cs
index 4e27d2d69..fef518fd0 100644
--- a/PKHeX/MainWindow/MainPK4.cs
+++ b/PKHeX/MainWindow/MainPK4.cs
@@ -134,7 +134,15 @@ private void populateFieldsPK4()
             {
                 int[] abils = SAV.Personal.getAbilities(pk4.Species, pk4.AltForm);
                 int abil = Array.IndexOf(abils, pk4.Ability);
-                CB_Ability.SelectedIndex = abil < 0 || abil >= CB_Ability.Items.Count ? 0 : abil;
+
+                if (abil < 0)
+                    CB_Ability.SelectedIndex = 0;
+                else if (abil == 2)
+                    CB_Ability.SelectedIndex = 2;
+                else if (abils[0] == abils[1] || abils[1] == 0)
+                    CB_Ability.SelectedIndex = pk4.PIDAbility;
+                else
+                    CB_Ability.SelectedIndex = abil < 0 || abil >= CB_Ability.Items.Count ? 0 : abil;
             }
         }
         private PKM preparePK4()
diff --git a/PKHeX/MainWindow/MainPK5.cs b/PKHeX/MainWindow/MainPK5.cs
index c48dde3d3..286871469 100644
--- a/PKHeX/MainWindow/MainPK5.cs
+++ b/PKHeX/MainWindow/MainPK5.cs
@@ -145,7 +145,15 @@ private void populateFieldsPK5()
             {
                 int[] abils = SAV.Personal.getAbilities(pk5.Species, pk5.AltForm);
                 int abil = Array.IndexOf(abils, pk5.Ability);
-                CB_Ability.SelectedIndex = abil < 0 || abil >= CB_Ability.Items.Count ? 0 : abil;
+
+                if (abil < 0)
+                    CB_Ability.SelectedIndex = 0;
+                else if (abil == 2)
+                    CB_Ability.SelectedIndex = 2;
+                else if (abils[0] == abils[1] || abils[1] == 0)
+                    CB_Ability.SelectedIndex = pk5.PIDAbility;
+                else
+                    CB_Ability.SelectedIndex = abil < 0 || abil >= CB_Ability.Items.Count ? 0 : abil;
             }
         }
         private PKM preparePK5()
diff --git a/PKHeX/PKM/PKM.cs b/PKHeX/PKM/PKM.cs
index 2c338ed30..949efd682 100644
--- a/PKHeX/PKM/PKM.cs
+++ b/PKHeX/PKM/PKM.cs
@@ -287,6 +287,17 @@ public int[] Moves
             get { return new[] { Move1, Move2, Move3, Move4 }; }
             set { if (value?.Length != 4) return; Move1 = value[0]; Move2 = value[1]; Move3 = value[2]; Move4 = value[3]; }
         }
+        public int PIDAbility
+        {
+            get
+            {
+                if (GenNumber > 5 || Format > 5)
+                    return -1;
+                if (GenNumber == 5)
+                    return (int)((PID >> 16) & 1);
+                return (int)(PID & 1);
+            }
+        }
 
         public bool[] Markings
         {