diff --git a/nshlib/nsh_builtin.c b/nshlib/nsh_builtin.c
index 583df84e3..49c0fd5d9 100644
--- a/nshlib/nsh_builtin.c
+++ b/nshlib/nsh_builtin.c
@@ -32,6 +32,7 @@
 #include <stdbool.h>
 #include <errno.h>
 #include <sched.h>
+#include <signal.h>
 #include <string.h>
 
 #include <nuttx/lib/builtin.h>