diff --git a/PKHeX.Core/Legality/Core.cs b/PKHeX.Core/Legality/Core.cs
index 419ed408d..9cc21cb92 100644
--- a/PKHeX.Core/Legality/Core.cs
+++ b/PKHeX.Core/Legality/Core.cs
@@ -463,8 +463,10 @@ private static bool IsEvolvedFormChange(PKM pkm, int expected)
                     return pkm.AltForm != orig; // bad compare?
                 if ((int) Species.Darmanitan == pkm.Species)
                     return pkm.AltForm == (expected == 1 ? 2 : 0);
-                if ((int)Species.MrMime == pkm.Species)
+                if ((int) Species.MrMime == pkm.Species)
                     return pkm.AltForm == (expected == 0 ? 1 : 0);
+                if ((int) Species.Slowbro == pkm.Species)
+                    return pkm.AltForm == (expected == 1 ? 2 : 0);
                 if ((int) Species.Toxtricity == pkm.Species)
                     return pkm.AltForm == EvolutionMethod.GetAmpLowKeyResult(pkm.Nature);
                 if ((int) Species.Alcremie == pkm.Species)