diff --git a/EnvelopeGenerator.Extensions/MemoryCacheExtensions.cs b/EnvelopeGenerator.Extensions/MemoryCacheExtensions.cs
index 31df714d..86ac56bb 100644
--- a/EnvelopeGenerator.Extensions/MemoryCacheExtensions.cs
+++ b/EnvelopeGenerator.Extensions/MemoryCacheExtensions.cs
@@ -1,20 +1,16 @@
 using Microsoft.Extensions.Caching.Memory;
-using System;
 
 namespace EnvelopeGenerator.Extensions;
 
 public static class MemoryCacheExtensions
 {
+    private static readonly Guid BaseId = Guid.NewGuid();
+
     public static IDictionary<string, int> GetEnumAsDictionary<TEnum>(this IMemoryCache memoryCache)
         where TEnum : Enum
-    {
-        var dict = new Dictionary<string, int>();
-
-        foreach (TEnum role in Enum.GetValues(typeof(TEnum)))
-        {
-            dict[role.ToString()] = Convert.ToInt32(role);
-        }
-
-        return dict;
-    }
+        => memoryCache.GetOrCreate(BaseId + typeof(TEnum).FullName, _ =>
+               Enum.GetValues(typeof(TEnum))
+                   .Cast<TEnum>()
+                   .ToDictionary(e => e.ToString(), e => Convert.ToInt32(e)))
+           ?? throw new InvalidOperationException($"Failed to cache or retrieve enum dictionary for type '{typeof(TEnum).FullName}'.");
 }
diff --git a/EnvelopeGenerator.GeneratorAPI/Controllers/HistoryController.cs b/EnvelopeGenerator.GeneratorAPI/Controllers/HistoryController.cs
index 2adbd4e0..5c55b567 100644
--- a/EnvelopeGenerator.GeneratorAPI/Controllers/HistoryController.cs
+++ b/EnvelopeGenerator.GeneratorAPI/Controllers/HistoryController.cs
@@ -5,7 +5,6 @@ using EnvelopeGenerator.Extensions;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Caching.Memory;
-using Microsoft.IdentityModel.Tokens;
 using static EnvelopeGenerator.Common.Constants;