diff --git a/package.json b/package.json
index 6ae6df2..b64c161 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "typing-assets",
-  "version": "2.1.3",
+  "version": "2.1.4",
   "description": "Additional typing assets and helpers for better TypeScript experience",
   "main": "build/index.js",
   "types": "build/index.d.ts",
diff --git a/src/functions/propertiesAggregation.ts b/src/functions/propertiesAggregation.ts
index 6d7c20d..05729ba 100644
--- a/src/functions/propertiesAggregation.ts
+++ b/src/functions/propertiesAggregation.ts
@@ -6,7 +6,10 @@
  */
 export const excludeProperties = <TSource, TProp extends keyof TSource> (source: TSource, ...args: TProp[]): Omit<TSource, TProp> => {
     for (const key in source) {
-        if ([...args].includes(key as string as TProp )) delete source[key]
+        if ([...args].includes(key as string as TProp )) {
+            source[key] = undefined as any
+            delete source[key]
+        }
     }
     return source
 }
@@ -20,7 +23,10 @@ export const excludeProperties = <TSource, TProp extends keyof TSource> (source:
  */
 export const pickProperties = <TSource, TProp extends keyof TSource>(source: TSource, ...args: TProp[]): Pick<TSource, TProp> => {
     for (const key in source) {
-        if (![...args].includes(key as string as TProp )) delete source[key]
+        if (![...args].includes(key as string as TProp )) {
+            source[key] = undefined as any
+            delete source[key]
+        }
     }
     return source
 }
\ No newline at end of file
diff --git a/src/utilityTypes/utility.ts b/src/utilityTypes/utility.ts
index 9737fb2..13479e3 100644
--- a/src/utilityTypes/utility.ts
+++ b/src/utilityTypes/utility.ts
@@ -36,5 +36,15 @@ export declare type ExcludeActual<T> = T extends object ? {
     [P in keyof T]: ExcludeActual<T[P]>
 } : Exclude<T, string | number | T[] | symbol | bigint>
 
-
+/**
+ * @description Returns actual return type of function, resolving all promises and excluding nullables
+ */
 export declare type ActualReturnType<T> = T extends (args: any[]) => Promise<any> ? ExcludeNullable<Awaited<ReturnType<T>>> : T extends (args: any[]) => any ? ExcludeNullable<ReturnType<T>> : never
+
+/**
+ * @description Changes type of property(es) to provided type primitive
+ * @T Providing type
+ * @P Property which type will be replaced
+ * @C Replacing type
+ */
+export type ChangePropertyType<T, P extends keyof T, C> = Omit<T, P> & { [P in keyof T]: C }
\ No newline at end of file