diff --git a/libs/libc/sched/sched_backtrace.c b/libs/libc/sched/sched_backtrace.c
index bc318cd02d3..5c35bdac1b0 100644
--- a/libs/libc/sched/sched_backtrace.c
+++ b/libs/libc/sched/sched_backtrace.c
@@ -25,6 +25,7 @@
 #include <nuttx/config.h>
 
 #include <sys/types.h>
+#include <unistd.h>
 #include <execinfo.h>
 #include <unwind.h>