diff --git a/Makefile b/Makefile
index 348519c..2e78b93 100644
--- a/Makefile
+++ b/Makefile
@@ -63,8 +63,8 @@ $(O)/obj/crt%.o: crt/crt%.c $(HEADERS)
 ### lib
 
 $(O)/lib/libc.a: $(OBJ_LIBC)
-	$(CROSS_COMPILE)ar rcs $@
-	$(foreach obj,$(OBJ_LIBC), \
+	@$(CROSS_COMPILE)ar rcs $@
+	@$(foreach obj,$(OBJ_LIBC), \
 		$(CROSS_COMPILE)ar rs $@ $(obj); \
 	)
 
diff --git a/include/_libc/signal.h b/include/_libc/signal.h
index c6258bd..c6ebf82 100644
--- a/include/_libc/signal.h
+++ b/include/_libc/signal.h
@@ -1,4 +1,6 @@
 #pragma once
+#include <signal.h>
 #define __LIBC_SIGNAL_STACK_SIZE        4096
 
+sighandler_t __libc_signal(int signum, sighandler_t h);
 void __libc_signal_init(void);
diff --git a/include/sys/wait.h b/include/sys/wait.h
new file mode 100644
index 0000000..48fb7db
--- /dev/null
+++ b/include/sys/wait.h
@@ -0,0 +1,5 @@
+#pragma once
+#include <ygg/types.h>
+#include <ygg/wait.h>
+
+pid_t waitpid(pid_t pid, int *status, int flags);
diff --git a/src/signal/impl.c b/src/signal/impl.c
index 63eeffe..03530d9 100644
--- a/src/signal/impl.c
+++ b/src/signal/impl.c
@@ -29,6 +29,16 @@ static _Noreturn void __libc_signal_handle(int signum) {
     while (1);
 }
 
+sighandler_t __libc_signal(int signum, sighandler_t s) {
+    if (signum >= NSIG || signum <= 0) {
+        exit(-1);
+    }
+
+    sighandler_t old = signal_handlers[signum];
+    signal_handlers[signum] = s;
+    return old;
+}
+
 void __libc_signal_init(void) {
     stack_t ss;
     void *sig_stack;
diff --git a/src/signal/kill.c b/src/signal/kill.c
new file mode 100644
index 0000000..432e2c8
--- /dev/null
+++ b/src/signal/kill.c
@@ -0,0 +1,8 @@
+#include <_libc/syscalls.h>
+#include <ygg/syscall.h>
+#include <signal.h>
+#include <errno.h>
+
+int kill(pid_t pid, int signum) {
+    return SET_ERRNO(int, __syscall2(SYSCALL_NR_KILL, pid, signum));
+}
diff --git a/src/signal/signal.c b/src/signal/signal.c
index e69de29..099f350 100644
--- a/src/signal/signal.c
+++ b/src/signal/signal.c
@@ -0,0 +1,5 @@
+#include <_libc/signal.h>
+
+sighandler_t signal(int signum, sighandler_t s) {
+    return __libc_signal(signum, s);
+}
diff --git a/src/sys/wait/waitpid.c b/src/sys/wait/waitpid.c
new file mode 100644
index 0000000..8125785
--- /dev/null
+++ b/src/sys/wait/waitpid.c
@@ -0,0 +1,8 @@
+#include <_libc/syscalls.h>
+#include <ygg/syscall.h>
+#include <sys/wait.h>
+#include <errno.h>
+
+pid_t waitpid(pid_t pid, int *status, int opt) {
+    return SET_ERRNO(pid_t, __syscall3(SYSCALL_NRX_WAITPID, pid, (long) status, opt));
+}