diff --git a/ocaml/TaskServer.ml b/ocaml/TaskServer.ml
index a1625719..abc2de1d 100644
--- a/ocaml/TaskServer.ml
+++ b/ocaml/TaskServer.ml
@@ -47,6 +47,14 @@ let debug str =
 let zmq_context =
   ZMQ.Context.create ()
 
+let () =
+  let nproc =
+    match Sys.getenv "OMP_NUM_THREADS" with
+    | Some m -> int_of_string m
+    | None -> 2
+  in
+  ZMQ.Context.set_io_threads zmq_context nproc
+
 
 let bind_socket ~socket_type ~socket ~port =
   let rec loop = function
diff --git a/src/ZMQ/utils.irp.f b/src/ZMQ/utils.irp.f
index 8e3a94e5..6bcf6e74 100644
--- a/src/ZMQ/utils.irp.f
+++ b/src/ZMQ/utils.irp.f
@@ -504,6 +504,11 @@ subroutine new_parallel_job(zmq_to_qp_run_socket,name_in)
   if (zmq_context == 0_ZMQ_PTR) then
      stop 'ZMQ_PTR is null'
   endif
+  rc = f77_zmq_ctx_set(zmq_context, ZMQ_IO_THREADS, nproc)
+  if (rc /= 0) then
+    print *,  'Unable to set the number of ZMQ IO threads to', nproc
+  endif
+
   zmq_to_qp_run_socket = new_zmq_to_qp_run_socket()
   name = name_in
   sze = len(trim(name))
@@ -584,7 +589,10 @@ subroutine end_parallel_job(zmq_to_qp_run_socket,name_in)
   zmq_state = 'No_state'
   call end_zmq_to_qp_run_socket(zmq_to_qp_run_socket)
 
+  call omp_set_lock(zmq_lock)
   rc = f77_zmq_ctx_term(zmq_context)
+  zmq_context = 0_ZMQ_PTR
+  call omp_unset_lock(zmq_lock)
   if (rc /= 0) then
     print *,  'Unable to terminate ZMQ context'
     stop 'error'