diff --git a/base-foc/src/base/thread/thread_start.cc b/base-foc/src/base/thread/thread_start.cc
index 2739d8be0..c64a05b62 100644
--- a/base-foc/src/base/thread/thread_start.cc
+++ b/base-foc/src/base/thread/thread_start.cc
@@ -61,6 +61,15 @@ void Thread_base::start()
 		l4_utcb_tcr_u(state.utcb)->user[UTCB_TCR_BADGE]      = state.id;
 		l4_utcb_tcr_u(state.utcb)->user[UTCB_TCR_THREAD_OBJ] = (addr_t)this;
 
+		/* there might be leaks in the application */
+		Cap_index *idx = cap_map()->find(state.id);
+		if (idx) {
+			idx->inc();
+			PWRN("leaking capability idx=%p id=%x ref_cnt=%d",
+			     idx, idx->id(), idx->dec());
+			cap_map()->remove(idx);
+		}
+
 		/* we need to manually increase the reference counter here */
 		cap_map()->insert(state.id, state.kcap)->inc();
 	} catch(Cap_index_allocator::Region_conflict) {