diff --git a/SightKeeper.Domain/Extensions.cs b/SightKeeper.Domain/Extensions.cs
index 0dca8648..911566b5 100644
--- a/SightKeeper.Domain/Extensions.cs
+++ b/SightKeeper.Domain/Extensions.cs
@@ -5,12 +5,6 @@ namespace SightKeeper.Domain;
 
 internal static class Extensions
 {
-	public static bool HasDuplicates<T>(this IEnumerable<T> enumerable)
-	{
-		HashSet<T> hashSet = new();
-		return !enumerable.All(hashSet.Add);
-	}
-
 	public static ImmutableHashSet<T> ToImmutableHashSetThrowOnDuplicate<T>(this IEnumerable<T> enumerable)
 	{
 		var tagsBuilder = ImmutableHashSet.CreateBuilder<T>();