diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index 2cdc96d6..961655ad 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -86,6 +86,7 @@ jobs:
                   cmake --build build --parallel 2
     test:
         runs-on: ubuntu-latest
+        timeout-minutes: 10
         steps:
             - name: Clone repository
               uses: actions/checkout@v4
diff --git a/mentos/src/hardware/timer.c b/mentos/src/hardware/timer.c
index 8b4009ec3..0ebf80b2 100644
--- a/mentos/src/hardware/timer.c
+++ b/mentos/src/hardware/timer.c
@@ -422,10 +422,14 @@ void run_timer_softirq(void)
             list_for_each_safe (it, tmp, &base->tv1.vec[current_time_index]) {
                 struct timer_list *timer = list_entry(it, struct timer_list, entry);
 
-                // Executes timer function
                 spinlock_unlock(&base->lock);
-                pr_debug("Executing dynamic timer function...\n");
-                timer->function(timer->data);
+                // Executes timer function
+                if (timer->function) {
+                    pr_debug("Executing dynamic timer function...\n");
+                    timer->function(timer->data);
+                } else {
+                    pr_alert("Dynamic timer function is NULL...\n");
+                }
                 spinlock_lock(&base->lock);
 
                 // Removes timer from list
diff --git a/programs/cat.c b/programs/cat.c
index c45692bd..fe01236c 100644
--- a/programs/cat.c
+++ b/programs/cat.c
@@ -55,6 +55,5 @@ int main(int argc, char **argv)
             ret = EXIT_FAILURE;
         }
     }
-    putchar('\n');
     return ret;
 }
diff --git a/programs/runtests.c b/programs/runtests.c
index 87be6ee3..bfd5fbc3 100644
--- a/programs/runtests.c
+++ b/programs/runtests.c
@@ -27,7 +27,7 @@
 static char *all_tests[] = {
     "t_abort",
     "t_alarm",
-    // "t_big_write",
+    /* "t_big_write", */
     "t_creat",
     "t_dup",
     "t_exec execl",