diff --git a/utils/availability-macros.def b/utils/availability-macros.def
index c8790c0753986..39611bd52444d 100644
--- a/utils/availability-macros.def
+++ b/utils/availability-macros.def
@@ -34,7 +34,7 @@ SwiftStdlib 5.6:macOS 12.3, iOS 15.4, watchOS 8.5, tvOS 15.4
 SwiftStdlib 5.7:macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0
 SwiftStdlib 5.8:macOS 13.3, iOS 16.4, watchOS 9.4, tvOS 16.4
 SwiftStdlib 5.9:macOS 14.0, iOS 17.0, watchOS 10.0, tvOS 17.0
-SwiftStdlib 5.10:macOS 9999, iOS 9999, watchOS 9999, tvOS 9999
+SwiftStdlib 5.10:macOS 14.4, iOS 17.4, watchOS 10.4, tvOS 17.4
 # TODO: Also update ASTContext::getSwift510Availability when needed
 
 # Local Variables: