diff --git a/definitions/objects/thread.def b/definitions/objects/thread.def
index 4e30a60..8ac3c8c 100644
--- a/definitions/objects/thread.def
+++ b/definitions/objects/thread.def
@@ -18,6 +18,6 @@ object thread : object {
     }
 
     method sleep [static] {
-        param until uint64
+        param duration uint64
     }
 }
diff --git a/src/kernel/syscalls/thread.cpp b/src/kernel/syscalls/thread.cpp
index 0d3c01e..22349c4 100644
--- a/src/kernel/syscalls/thread.cpp
+++ b/src/kernel/syscalls/thread.cpp
@@ -1,6 +1,7 @@
 #include <j6/errors.h>
 #include <j6/types.h>
 
+#include "clock.h"
 #include "logger.h"
 #include "objects/process.h"
 #include "objects/thread.h"
@@ -47,11 +48,13 @@ thread_kill(thread *self)
 }
 
 j6_status_t
-thread_sleep(uint64_t til)
+thread_sleep(uint64_t duration)
 {
     thread &th = thread::current();
-    log::debug(logs::task, "Thread %llx sleeping until %llu", th.koid(), til);
 
+    uint64_t til = clock::get().value() + duration;
+
+    log::debug(logs::task, "Thread %llx sleeping until %llu", th.koid(), til);
     th.set_wake_timeout(til);
     th.block();
     return j6_status_ok;