diff --git a/sys/ps/ps.c b/sys/ps/ps.c
index 600dad0cbb..457c871ed0 100644
--- a/sys/ps/ps.c
+++ b/sys/ps/ps.c
@@ -15,12 +15,12 @@
  * @}
  */
 
-#include <thread.h>
-#include <thread.h>
-#include <hwtimer.h>
-#include <sched.h>
 #include <stdio.h>
 
+#include "thread.h"
+#include "hwtimer.h"
+#include "sched.h"
+
 /* list of states copied from tcb.h */
 const char *state_names[] = {
     "running",