diff --git a/kernel/time.c b/kernel/time.c
index d46c8d5f86..dd8d80c11c 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -274,8 +274,10 @@ int_t sys_timer_create(dword_t clock, addr_t sigevent_addr, addr_t timer_addr) {
 
     if (sigev.method == SIGEV_THREAD_ID_) {
         lock(&pids_lock);
-        if (pid_get_task(sigev.tid) == NULL)
+        if (pid_get_task(sigev.tid) == NULL) {
+            unlock(&pids_lock);
             return _EINVAL;
+        }
         unlock(&pids_lock);
     }