diff --git a/src/Perf/IIDOptimizer/SignatureEmitter.cs b/src/Perf/IIDOptimizer/SignatureEmitter.cs
index 3b2ad2911..45248a7a6 100644
--- a/src/Perf/IIDOptimizer/SignatureEmitter.cs
+++ b/src/Perf/IIDOptimizer/SignatureEmitter.cs
@@ -163,18 +163,6 @@ private void GenerateGuidFactoryFromComplexSignature(TypeDefinition implementati
                 getterMethodGensToCacheTypeGens[guidDataGetterMethod.GenericParameters[i]] = cacheType.GenericParameters[i];
             }
 
-            var instantiatedCacheType = new GenericInstanceType(cacheType);
-            foreach (var arg in guidDataGetterMethod.GenericParameters)
-            {
-                instantiatedCacheType.GenericArguments.Add(arg);
-            }
-
-            var selfInstantiatedCacheType = new GenericInstanceType(cacheType);
-            foreach (var param in cacheType.GenericParameters)
-            {
-                selfInstantiatedCacheType.GenericArguments.Add(param);
-            }
-
             var cacheField = new FieldDefinition("iidData", FieldAttributes.Static | FieldAttributes.Assembly, new ArrayType(module.ImportReference(module.TypeSystem.Byte)));
             cacheType.Fields.Add(cacheField);
             implementationDetailsType.NestedTypes.Add(cacheType);
@@ -185,7 +173,7 @@ private void GenerateGuidFactoryFromComplexSignature(TypeDefinition implementati
 
             // In the body of the getter method, return the cache data
             var getterIL = guidDataGetterMethod.Body.GetILProcessor();
-            getterIL.Emit(OpCodes.Ldsfld, new FieldReference(cacheField.Name, cacheField.FieldType, instantiatedCacheType));
+            getterIL.Emit(OpCodes.Ldsfld, new FieldReference(cacheField.Name, cacheField.FieldType, cacheType));
             getterIL.Emit(OpCodes.Newobj, readOnlySpanOfByteArrayCtor);
             getterIL.Emit(OpCodes.Ret);
 
@@ -598,7 +586,7 @@ private void GenerateGuidFactoryFromComplexSignature(TypeDefinition implementati
             il.Emit(OpCodes.Stloc, spanTemp);
             il.Emit(OpCodes.Ldloca, spanTemp);
             il.Emit(OpCodes.Call, toArrayMethod);
-            il.Emit(OpCodes.Stsfld, new FieldReference(cacheField.Name, cacheField.FieldType, selfInstantiatedCacheType));
+            il.Emit(OpCodes.Stsfld, new FieldReference(cacheField.Name, cacheField.FieldType, cacheType));
             il.Emit(OpCodes.Ret);
         }
     }