diff --git a/Sources/Fetching and Querying/Concrete Clauses/Where.swift b/Sources/Fetching and Querying/Concrete Clauses/Where.swift
index 8704477..4d7a20f 100644
--- a/Sources/Fetching and Querying/Concrete Clauses/Where.swift	
+++ b/Sources/Fetching and Querying/Concrete Clauses/Where.swift	
@@ -119,7 +119,7 @@ public struct Where: FetchClause, QueryClause, DeleteClause, Hashable {
      - parameter keyPath: the keyPath to compare with
      - parameter list: the array to check membership of
      */
-    public init(_ keyPath: KeyPath, isMemberOf list: NSArray) {
+    public init(_ keyPath: KeyPath, isMemberOf list: [NSObject]) {
         
         self.init(NSPredicate(format: "\(keyPath) IN %@", list))
     }
diff --git a/Sources/ObjectiveC/CSWhere.swift b/Sources/ObjectiveC/CSWhere.swift
index b88b0d5..5008ca4 100644
--- a/Sources/ObjectiveC/CSWhere.swift
+++ b/Sources/ObjectiveC/CSWhere.swift
@@ -93,7 +93,7 @@ public final class CSWhere: NSObject, CSFetchClause, CSQueryClause, CSDeleteClau
      - returns: a `CSWhere` clause that compares membership
      */
     @objc
-    public static func keyPath(keyPath: KeyPath, isMemberOf list: NSArray) -> CSWhere {
+    public static func keyPath(keyPath: KeyPath, isMemberOf list: [NSObject]) -> CSWhere {
         
         return self.init(Where(keyPath, isMemberOf: list))
     }