diff -r -u source/src/irods-grid.cpp source.new/src/irods-grid.cpp
--- source/src/irods-grid.cpp	1970-01-01 01:00:01.000000000 +0100
+++ source.new/src/irods-grid.cpp	2020-05-05 16:34:35.566464346 +0200
@@ -412,7 +412,7 @@
             data_to_send.data(),
             data_to_send.size() );
         try {
-            if (!zmq_skt.send(req)) {
+            if (!zmq_skt.send( req, zmq::send_flags::dontwait )) {
                 std::cerr << "ZeroMQ encountered an error sending a message.\n";
                 return errno;
             }
@@ -426,7 +426,7 @@
         zmq::message_t rep;
         // wait for the server reponse
         try {
-            if (!zmq_skt.recv( &rep )) {
+            if (!zmq_skt.recv( rep, zmq::recv_flags::dontwait )) {
                 std::cerr << "ZeroMQ encountered an error receiving a message.\n";
                 return errno;
             }