diff --git a/fs/tty.c b/fs/tty.c
index 9e92686dac..d0d410a69f 100644
--- a/fs/tty.c
+++ b/fs/tty.c
@@ -364,7 +364,7 @@ ssize_t tty_input(struct tty *tty, const char *input, size_t size, bool blocking
     unlock(&tty->lock);
 
     if (fg_group != 0) {
-        for (int sig = 1; sig <= NUM_SIGS; sig++) {
+        for (int sig = 1; sig < NUM_SIGS; sig++) {
             if (sigset_has(queue, sig))
                 send_group_signal(fg_group, sig, SIGINFO_NIL);
         }
diff --git a/kernel/signal.h b/kernel/signal.h
index 5d617926e8..00fb737056 100644
--- a/kernel/signal.h
+++ b/kernel/signal.h
@@ -145,7 +145,7 @@ dword_t sys_rt_sigprocmask(dword_t how, addr_t set, addr_t oldset, dword_t size)
 int_t sys_rt_sigpending(addr_t set_addr);
 
 static inline sigset_t_ sig_mask(int sig) {
-    assert(sig >= 1 && sig <= NUM_SIGS);
+    assert(sig >= 1 && sig < NUM_SIGS);
     return 1l << (sig - 1);
 }