diff --git a/src/data_structures/synchronizer.ml b/src/data_structures/synchronizer.ml
index de19fb47..39bd8dbb 100644
--- a/src/data_structures/synchronizer.ml
+++ b/src/data_structures/synchronizer.ml
@@ -46,7 +46,7 @@ let make_pledge synchro =
 let end_pledge synchro =
   Mutex.lock synchro.mutex;
   synchro.pledges <- synchro.pledges - 1;
-  Condition.broadcast synchro.cond;
+  if Int.equal synchro.pledges 0 then Condition.broadcast synchro.cond;
   Mutex.unlock synchro.mutex
 
 let fail q =
diff --git a/src/data_structures/wq.ml b/src/data_structures/wq.ml
index 842ec824..3548b555 100644
--- a/src/data_structures/wq.ml
+++ b/src/data_structures/wq.ml
@@ -27,8 +27,7 @@ let fail = Synchronizer.fail
 let make () =
   let q = Queue.create () in
   let writter v condvar =
-    let was_empty = Queue.is_empty q in
     Queue.push v q;
-    if was_empty then Condition.broadcast condvar
+    Condition.signal condvar
   in
   Synchronizer.init (fun () -> Queue.take_opt q) writter