diff --git a/Foundation/NSData.swift b/Foundation/NSData.swift
index b6e3d4c8be..37ac6bf3f4 100644
--- a/Foundation/NSData.swift
+++ b/Foundation/NSData.swift
@@ -587,7 +587,7 @@ open class NSData : NSObject, NSCopying, NSMutableCopying, NSSecureCoding {
         }
         return location.map {NSRange(location: $0, length: search.count)} ?? NSRange(location: NSNotFound, length: 0)
     }
-    private static func searchSubSequence<T : Collection, T2 : Sequence>(_ subSequence : T2, inSequence seq: T,anchored : Bool) -> T.Index? where T.Iterator.Element : Equatable, T.Iterator.Element == T2.Iterator.Element, T.SubSequence.Iterator.Element == T.Iterator.Element, T.Indices.Iterator.Element == T.Index {
+    private static func searchSubSequence<T : Collection, T2 : Sequence>(_ subSequence : T2, inSequence seq: T,anchored : Bool) -> T.Index? where T.Iterator.Element : Equatable, T.Iterator.Element == T2.Iterator.Element {
         for index in seq.indices {
             if seq.suffix(from: index).starts(with: subSequence) {
                 return index