diff --git a/PKHeX.Core/Legality/Encounters/Verifiers/VerifyRelearnMoves.cs b/PKHeX.Core/Legality/Encounters/Verifiers/VerifyRelearnMoves.cs
index 024d058d3..eead22cf9 100644
--- a/PKHeX.Core/Legality/Encounters/Verifiers/VerifyRelearnMoves.cs
+++ b/PKHeX.Core/Legality/Encounters/Verifiers/VerifyRelearnMoves.cs
@@ -126,6 +126,9 @@ private static CheckResult[] VerifyRelearnEggBase(PKM pkm, EncounterEgg e)
             if (splitInvalid && e is EncounterEggSplit x)
                 FlagSplitbreedMoves(result, reqBase, x);
 
+            var dupe = IsAnyRelearnMoveDuplicate(pkm);
+            if (dupe > 0)
+                result[dupe] = new CheckResult(Severity.Invalid, LMoveSourceDuplicate, CheckIdentifier.RelearnMove);
             return result;
         }
 
@@ -197,5 +200,21 @@ private static int GetRequiredBaseMoves(int[] RelearnMoves, IReadOnlyList<int> b
                 reqBase = Math.Min(4, unique);
             return reqBase;
         }
+
+        private static int IsAnyRelearnMoveDuplicate(PKM pk)
+        {
+            int m1 = pk.RelearnMove1;
+            int m2 = pk.RelearnMove2;
+
+            if (m1 != 0 && m1 == m2)
+                return 1;
+            int m3 = pk.RelearnMove3;
+            if (m3 != 0 && (m1 == m3 || m2 == m3))
+                return 2;
+            int m4 = pk.RelearnMove4;
+            if (m4 != 0 && (m1 == m4 || m2 == m4 || m3 == m4))
+                return 3;
+            return -1;
+        }
     }
 }