diff --git a/types/joi/index.d.ts b/types/joi/index.d.ts
index c11bcb9daf..b1696bb7ad 100644
--- a/types/joi/index.d.ts
+++ b/types/joi/index.d.ts
@@ -567,7 +567,8 @@ export interface ArraySchema extends AnySchema<ArraySchema> {
      * Be aware that a deep equality is performed on elements of the array having a type of object,
      * a performance penalty is to be expected for this kind of operation.
      */
-    unique(): ArraySchema;
+    unique(comparator?: (a: any, b: any) => boolean): ArraySchema;
+    unique(comparator?: string): ArraySchema;
 }
 
 export interface ObjectSchema extends AnySchema<ObjectSchema> {
diff --git a/types/joi/joi-tests.ts b/types/joi/joi-tests.ts
index f35a124183..a58623ea06 100644
--- a/types/joi/joi-tests.ts
+++ b/types/joi/joi-tests.ts
@@ -261,6 +261,8 @@ arrSchema = arrSchema.min(num);
 arrSchema = arrSchema.max(num);
 arrSchema = arrSchema.length(num);
 arrSchema = arrSchema.unique();
+arrSchema = arrSchema.unique((a, b) => a.test === b.test);
+arrSchema = arrSchema.unique('customer.id');
 
 
 arrSchema = arrSchema.items(numSchema);