diff --git a/kernel/include/sortix/kernel/time.h b/kernel/include/sortix/kernel/time.h
index 03c67573..f6e06e61 100644
--- a/kernel/include/sortix/kernel/time.h
+++ b/kernel/include/sortix/kernel/time.h
@@ -25,12 +25,9 @@
 #ifndef INCLUDE_SORTIX_KERNEL_TIME_H
 #define INCLUDE_SORTIX_KERNEL_TIME_H
 
-#include <features.h>
-
+#include <sys/cdefs.h>
 #include <sys/types.h>
 
-#include <stddef.h>
-
 #include <sortix/timespec.h>
 
 namespace Sortix {
diff --git a/libpthread/include/semaphore.h b/libpthread/include/semaphore.h
index a5bd370d..1e8ddb02 100644
--- a/libpthread/include/semaphore.h
+++ b/libpthread/include/semaphore.h
@@ -25,7 +25,7 @@
 #ifndef INCLUDE_SEMAPHORE_H
 #define INCLUDE_SEMAPHORE_H
 
-#include <features.h>
+#include <sys/cdefs.h>
 
 #include <sortix/timespec.h>