diff --git a/core/cond.c b/core/cond.c
index 8ff45f4d7461..497956496987 100644
--- a/core/cond.c
+++ b/core/cond.c
@@ -34,13 +34,14 @@ void cond_init(cond_t *cond)
 
 void cond_wait(cond_t *cond, mutex_t *mutex)
 {
-    unsigned irqstate = irq_disable();
+    assert(irq_is_enabled());
+    irq_disable();
     thread_t *me = thread_get_active();
 
     mutex_unlock(mutex);
     sched_set_status(me, STATUS_COND_BLOCKED);
     thread_add_to_list(&cond->queue, me);
-    irq_restore(irqstate);
+    irq_enable();
     thread_yield_higher();
 
     /*