diff --git a/Sources/AsyncAlgorithms/AsyncAdjacentPairsSequence.swift b/Sources/AsyncAlgorithms/AsyncAdjacentPairsSequence.swift
index 7a69bf35..2a37f918 100644
--- a/Sources/AsyncAlgorithms/AsyncAdjacentPairsSequence.swift
+++ b/Sources/AsyncAlgorithms/AsyncAdjacentPairsSequence.swift
@@ -83,5 +83,7 @@ extension AsyncSequence {
   }
 }
 
-extension AsyncAdjacentPairsSequence: Sendable where Base: Sendable, Base.Element: Sendable, Base.AsyncIterator: Sendable { }
-extension AsyncAdjacentPairsSequence.Iterator: Sendable where Base: Sendable, Base.Element: Sendable, Base.AsyncIterator: Sendable { }
+extension AsyncAdjacentPairsSequence: Sendable where Base: Sendable, Base.Element: Sendable { }
+
+@available(*, unavailable)
+extension AsyncAdjacentPairsSequence.Iterator: Sendable { }