diff --git a/osdep/mac/swift_compat.swift b/osdep/mac/swift_compat.swift
index 24365cdd4a..bac1abe082 100644
--- a/osdep/mac/swift_compat.swift
+++ b/osdep/mac/swift_compat.swift
@@ -16,7 +16,7 @@
  */
 
 #if !swift(>=5.7)
-extension NSCondition {
+extension NSLocking {
     func withLock<R>(_ body: () throws -> R) rethrows -> R {
         self.lock()
         defer { self.unlock() }