diff --git a/tests/test_spec_dealer.cpp b/tests/test_spec_dealer.cpp
index 1235f26b..fc7ef277 100644
--- a/tests/test_spec_dealer.cpp
+++ b/tests/test_spec_dealer.cpp
@@ -21,12 +21,15 @@
 #include <stdlib.h>
 #include "testutil.hpp"
 
+const char *bind_address = 0;
+const char *connect_address = 0;
+
 void test_round_robin_out (void *ctx)
 {
     void *dealer = zmq_socket (ctx, ZMQ_DEALER);
     assert (dealer);
 
-    int rc = zmq_bind (dealer, "inproc://b");
+    int rc = zmq_bind (dealer, bind_address);
     assert (rc == 0);
 
     const size_t N = 5;
@@ -40,10 +43,14 @@ void test_round_robin_out (void *ctx)
         rc = zmq_setsockopt (rep[i], ZMQ_RCVTIMEO, &timeout, sizeof(int));
         assert (rc == 0);
 
-        rc = zmq_connect (rep[i], "inproc://b");
+        rc = zmq_connect (rep[i], connect_address);
         assert (rc == 0);
     }
 
+    // Wait for connections.
+    rc = zmq_poll (0, 0, 100);
+    assert (rc == 0);
+
     // Send N requests
     for (size_t i = 0; i < N; ++i)
     {
@@ -62,14 +69,16 @@ void test_round_robin_out (void *ctx)
     rc = zmq_msg_close (&msg);
     assert (rc == 0);
 
-    rc = zmq_close (dealer);
-    assert (rc == 0);
+    close_zero_linger (dealer);
 
     for (size_t i = 0; i < N; ++i)
     {
-        rc = zmq_close (rep[i]);
-        assert (rc == 0);
+        close_zero_linger (rep[i]);
     }
+
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
+    assert (rc == 0);
 }
 
 void test_fair_queue_in (void *ctx)
@@ -81,7 +90,7 @@ void test_fair_queue_in (void *ctx)
     int rc = zmq_setsockopt (receiver, ZMQ_RCVTIMEO, &timeout, sizeof(int));
     assert (rc == 0);
 
-    rc = zmq_bind (receiver, "inproc://a");
+    rc = zmq_bind (receiver, bind_address);
     assert (rc == 0);
 
     const size_t N = 5;
@@ -94,7 +103,7 @@ void test_fair_queue_in (void *ctx)
         rc = zmq_setsockopt (senders[i], ZMQ_RCVTIMEO, &timeout, sizeof(int));
         assert (rc == 0);
 
-        rc = zmq_connect (senders[i], "inproc://a");
+        rc = zmq_connect (senders[i], connect_address);
         assert (rc == 0);
     }
 
@@ -111,32 +120,32 @@ void test_fair_queue_in (void *ctx)
     // send N requests
     for (size_t i = 0; i < N; ++i)
     {
-        char *str = strdup("A");
-        str[0] += i;
-        s_send_seq (senders[i], str, SEQ_END);
-        free (str);
+        s_send_seq (senders[i], "B", SEQ_END);
     }
 
+    // Wait for data.
+    rc = zmq_poll (0, 0, 50);
+    assert (rc == 0);
+
     // handle N requests
     for (size_t i = 0; i < N; ++i)
     {
-        char *str = strdup("A");
-        str[0] += i;
-        s_recv_seq (receiver, str, SEQ_END);
-        free (str);
+        s_recv_seq (receiver, "B", SEQ_END);
     }
 
     rc = zmq_msg_close (&msg);
     assert (rc == 0);
 
-    rc = zmq_close (receiver);
-    assert (rc == 0);
+    close_zero_linger (receiver);
 
     for (size_t i = 0; i < N; ++i)
     {
-        rc = zmq_close (senders[i]);
-        assert (rc == 0);
+        close_zero_linger (senders[i]);
     }
+
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
+    assert (rc == 0);
 }
 
 void test_destroy_queue_on_disconnect (void *ctx)
@@ -144,26 +153,28 @@ void test_destroy_queue_on_disconnect (void *ctx)
     void *A = zmq_socket (ctx, ZMQ_DEALER);
     assert (A);
 
-    int rc = zmq_bind (A, "inproc://d");
+    int rc = zmq_bind (A, bind_address);
     assert (rc == 0);
 
     void *B = zmq_socket (ctx, ZMQ_DEALER);
     assert (B);
 
-    rc = zmq_connect (B, "inproc://d");
+    rc = zmq_connect (B, connect_address);
     assert (rc == 0);
 
     // Send a message in both directions
     s_send_seq (A, "ABC", SEQ_END);
     s_send_seq (B, "DEF", SEQ_END);
 
-    rc = zmq_disconnect (B, "inproc://d");
+    rc = zmq_disconnect (B, connect_address);
     assert (rc == 0);
 
     // Disconnect may take time and need command processing.
     zmq_pollitem_t poller[2] = { { A, 0, 0, 0 }, { B, 0, 0, 0 } };
     rc = zmq_poll (poller, 2, 100);
     assert (rc == 0);
+    rc = zmq_poll (poller, 2, 100);
+    assert (rc == 0);
 
     // No messages should be available, sending should fail.
     zmq_msg_t msg;
@@ -178,7 +189,7 @@ void test_destroy_queue_on_disconnect (void *ctx)
     assert (errno == EAGAIN);
 
     // After a reconnect of B, the messages should still be gone
-    rc = zmq_connect (B, "inproc://d");
+    rc = zmq_connect (B, connect_address);
     assert (rc == 0);
 
     rc = zmq_msg_recv (&msg, A, ZMQ_DONTWAIT);
@@ -192,10 +203,11 @@ void test_destroy_queue_on_disconnect (void *ctx)
     rc = zmq_msg_close (&msg);
     assert (rc == 0);
 
-    rc = zmq_close (A);
-    assert (rc == 0);
+    close_zero_linger (A);
+    close_zero_linger (B);
 
-    rc = zmq_close (B);
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
     assert (rc == 0);
 }
 
@@ -225,21 +237,29 @@ int main ()
     void *ctx = zmq_ctx_new ();
     assert (ctx);
 
-    // SHALL route outgoing messages to available peers using a round-robin
-    // strategy.
-    test_round_robin_out (ctx);
+    const char *binds[] =    { "inproc://a", "tcp://*:5555" };
+    const char *connects[] = { "inproc://a", "tcp://localhost:5555" };
 
-    // SHALL receive incoming messages from its peers using a fair-queuing
-    // strategy.
-    test_fair_queue_in (ctx);
+    for (int i = 0; i < 2; ++i) {
+        bind_address = binds[i];
+        connect_address = connects[i];
 
-    // SHALL block on sending, or return a suitable error, when it has no connected peers.
-    test_block_on_send_no_peers (ctx);
+        // SHALL route outgoing messages to available peers using a round-robin
+        // strategy.
+        test_round_robin_out (ctx);
 
-    // SHALL create a double queue when a peer connects to it. If this peer
-    // disconnects, the DEALER socket SHALL destroy its double queue and SHALL
-    // discard any messages it contains.
-    test_destroy_queue_on_disconnect (ctx);
+        // SHALL receive incoming messages from its peers using a fair-queuing
+        // strategy.
+        test_fair_queue_in (ctx);
+
+        // SHALL block on sending, or return a suitable error, when it has no connected peers.
+        test_block_on_send_no_peers (ctx);
+
+        // SHALL create a double queue when a peer connects to it. If this peer
+        // disconnects, the DEALER socket SHALL destroy its double queue and SHALL
+        // discard any messages it contains.
+        test_destroy_queue_on_disconnect (ctx);
+    }
 
     int rc = zmq_ctx_term (ctx);
     assert (rc == 0);
diff --git a/tests/test_spec_pushpull.cpp b/tests/test_spec_pushpull.cpp
index 764525cf..a91d3c74 100644
--- a/tests/test_spec_pushpull.cpp
+++ b/tests/test_spec_pushpull.cpp
@@ -21,12 +21,15 @@
 #include <stdlib.h>
 #include "testutil.hpp"
 
+const char *bind_address = 0;
+const char *connect_address = 0;
+
 void test_push_round_robin_out (void *ctx)
 {
     void *push = zmq_socket (ctx, ZMQ_PUSH);
     assert (push);
 
-    int rc = zmq_bind (push, "inproc://b");
+    int rc = zmq_bind (push, bind_address);
     assert (rc == 0);
 
     const size_t N = 5;
@@ -40,10 +43,14 @@ void test_push_round_robin_out (void *ctx)
         rc = zmq_setsockopt (pulls[i], ZMQ_RCVTIMEO, &timeout, sizeof(int));
         assert (rc == 0);
 
-        rc = zmq_connect (pulls[i], "inproc://b");
+        rc = zmq_connect (pulls[i], connect_address);
         assert (rc == 0);
     }
 
+    // Wait for connections.
+    rc = zmq_poll (0, 0, 100);
+    assert (rc == 0);
+
     // Send 2N messages
     for (size_t i = 0; i < N; ++i)
     {
@@ -61,14 +68,16 @@ void test_push_round_robin_out (void *ctx)
         s_recv_seq (pulls[i], "DEF", SEQ_END);
     }
 
-    rc = zmq_close (push);
-    assert (rc == 0);
+    close_zero_linger (push);
 
     for (size_t i = 0; i < N; ++i)
     {
-        rc = zmq_close (pulls[i]);
-        assert (rc == 0);
+        close_zero_linger (pulls[i]);
     }
+
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
+    assert (rc == 0);
 }
 
 void test_pull_fair_queue_in (void *ctx)
@@ -76,7 +85,7 @@ void test_pull_fair_queue_in (void *ctx)
     void *pull = zmq_socket (ctx, ZMQ_PULL);
     assert (pull);
 
-    int rc = zmq_bind (pull, "inproc://a");
+    int rc = zmq_bind (pull, bind_address);
     assert (rc == 0);
 
     const size_t N = 5;
@@ -86,38 +95,74 @@ void test_pull_fair_queue_in (void *ctx)
         pushs[i] = zmq_socket (ctx, ZMQ_PUSH);
         assert (pushs[i]);
 
-        rc = zmq_connect (pushs[i], "inproc://a");
+        rc = zmq_connect (pushs[i], connect_address);
         assert (rc == 0);
     }
 
+    // Wait for connections.
+    rc = zmq_poll (0, 0, 100);
+    assert (rc == 0);
+
+    int first_half = 0;
+    int second_half = 0;
+
     // Send 2N messages
     for (size_t i = 0; i < N; ++i)
     {
-        char * str = strdup("A");
+        char *str = strdup("A");
+
         str[0] += i;
         s_send_seq (pushs[i], str, SEQ_END);
+        first_half += str[0];
+
         str[0] += N;
         s_send_seq (pushs[i], str, SEQ_END);
+        second_half += str[0];
+
         free (str);
     }
 
-    // Expect to pull them in order
-    for (size_t i = 0; i < 2*N; ++i)
-    {
-        char * str = strdup("A");
-        str[0] += i;
-        s_recv_seq (pull, str, SEQ_END);
-        free (str);
-    }
-
-    rc = zmq_close (pull);
+    // Wait for data.
+    rc = zmq_poll (0, 0, 100);
     assert (rc == 0);
 
+    zmq_msg_t msg;
+    rc = zmq_msg_init (&msg);
+    assert (rc == 0);
+
+    // Expect to pull one from each first
+    for (size_t i = 0; i < N; ++i)
+    {
+        rc = zmq_msg_recv (&msg, pull, 0);
+        assert (rc == 2);
+        const char *str = (const char *)zmq_msg_data (&msg);
+        first_half -= str[0];
+    }
+    assert (first_half == 0);
+
+    // And then get the second batch
+    for (size_t i = 0; i < N; ++i)
+    {
+        rc = zmq_msg_recv (&msg, pull, 0);
+        assert (rc == 2);
+        const char *str = (const char *)zmq_msg_data (&msg);
+        second_half -= str[0];
+    }
+    assert (second_half == 0);
+
+    rc = zmq_msg_close (&msg);
+    assert (rc == 0);
+
+    close_zero_linger (pull);
+
     for (size_t i = 0; i < N; ++i)
     {
-        rc = zmq_close (pushs[i]);
-        assert (rc == 0);
+        close_zero_linger (pushs[i]);
     }
+
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
+    assert (rc == 0);
 }
 
 void test_push_block_on_send_no_peers (void *ctx)
@@ -150,7 +195,7 @@ void test_destroy_queue_on_disconnect (void *ctx)
     int rc = zmq_setsockopt (A, ZMQ_SNDHWM, &hwm, sizeof(hwm));
     assert (rc == 0);
 
-    rc = zmq_bind (A, "inproc://d");
+    rc = zmq_bind (A, bind_address);
     assert (rc == 0);
 
     void *B = zmq_socket (ctx, ZMQ_PULL);
@@ -159,7 +204,7 @@ void test_destroy_queue_on_disconnect (void *ctx)
     rc = zmq_setsockopt (B, ZMQ_RCVHWM, &hwm, sizeof(hwm));
     assert (rc == 0);
 
-    rc = zmq_connect (B, "inproc://d");
+    rc = zmq_connect (B, connect_address);
     assert (rc == 0);
 
     // Send two messages, one should be stuck in A's outgoing queue, the other
@@ -172,13 +217,15 @@ void test_destroy_queue_on_disconnect (void *ctx)
     assert (rc == -1);
     assert (errno == EAGAIN);
 
-    rc = zmq_disconnect (B, "inproc://d");
+    rc = zmq_disconnect (B, connect_address);
     assert (rc == 0);
 
     // Disconnect may take time and need command processing.
     zmq_pollitem_t poller[2] = { { A, 0, 0, 0 }, { B, 0, 0, 0 } };
     rc = zmq_poll (poller, 2, 100);
     assert (rc == 0);
+    rc = zmq_poll (poller, 2, 100);
+    assert (rc == 0);
 
     zmq_msg_t msg;
     rc = zmq_msg_init (&msg);
@@ -195,7 +242,7 @@ void test_destroy_queue_on_disconnect (void *ctx)
     assert (errno == EAGAIN);
 
     // Reconnect B
-    rc = zmq_connect (B, "inproc://d");
+    rc = zmq_connect (B, connect_address);
     assert (rc == 0);
 
     // Still can't receive old data on B.
@@ -214,10 +261,11 @@ void test_destroy_queue_on_disconnect (void *ctx)
     rc = zmq_msg_close (&msg);
     assert (rc == 0);
 
-    rc = zmq_close (A);
-    assert (rc == 0);
+    close_zero_linger (A);
+    close_zero_linger (B);
 
-    rc = zmq_close (B);
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
     assert (rc == 0);
 }
 
@@ -226,22 +274,30 @@ int main ()
     void *ctx = zmq_ctx_new ();
     assert (ctx);
 
-    // PUSH: SHALL route outgoing messages to connected peers using a
-    // round-robin strategy.
-    test_push_round_robin_out (ctx);
+    const char *binds[] =    { "inproc://a", "tcp://*:5555" };
+    const char *connects[] = { "inproc://a", "tcp://localhost:5555" };
 
-    // PULL: SHALL receive incoming messages from its peers using a fair-queuing
-    // strategy.
-    test_pull_fair_queue_in (ctx);
+    for (int i = 0; i < 2; ++i) {
+        bind_address = binds[i];
+        connect_address = connects[i];
 
-    // PUSH: SHALL block on sending, or return a suitable error, when it has no
-    // available peers.
-    test_push_block_on_send_no_peers (ctx);
+        // PUSH: SHALL route outgoing messages to connected peers using a
+        // round-robin strategy.
+        test_push_round_robin_out (ctx);
 
-    // PUSH and PULL: SHALL create this queue when a peer connects to it. If
-    // this peer disconnects, the socket SHALL destroy its queue and SHALL
-    // discard any messages it contains.
-    test_destroy_queue_on_disconnect (ctx);
+        // PULL: SHALL receive incoming messages from its peers using a fair-queuing
+        // strategy.
+        test_pull_fair_queue_in (ctx);
+
+        // PUSH: SHALL block on sending, or return a suitable error, when it has no
+        // available peers.
+        test_push_block_on_send_no_peers (ctx);
+
+        // PUSH and PULL: SHALL create this queue when a peer connects to it. If
+        // this peer disconnects, the socket SHALL destroy its queue and SHALL
+        // discard any messages it contains.
+        test_destroy_queue_on_disconnect (ctx);
+    }
 
     int rc = zmq_ctx_term (ctx);
     assert (rc == 0);
diff --git a/tests/test_spec_rep.cpp b/tests/test_spec_rep.cpp
index 2f1424aa..53402e45 100644
--- a/tests/test_spec_rep.cpp
+++ b/tests/test_spec_rep.cpp
@@ -21,6 +21,9 @@
 #include <stdlib.h>
 #include "testutil.hpp"
 
+const char *bind_address = 0;
+const char *connect_address = 0;
+
 void test_fair_queue_in (void *ctx)
 {
     void *rep = zmq_socket (ctx, ZMQ_REP);
@@ -30,7 +33,7 @@ void test_fair_queue_in (void *ctx)
     int rc = zmq_setsockopt (rep, ZMQ_RCVTIMEO, &timeout, sizeof(int));
     assert (rc == 0);
 
-    rc = zmq_bind (rep, "inproc://a");
+    rc = zmq_bind (rep, bind_address);
     assert (rc == 0);
 
     const size_t N = 5;
@@ -43,7 +46,7 @@ void test_fair_queue_in (void *ctx)
         rc = zmq_setsockopt (reqs[i], ZMQ_RCVTIMEO, &timeout, sizeof(int));
         assert (rc == 0);
 
-        rc = zmq_connect (reqs[i], "inproc://a");
+        rc = zmq_connect (reqs[i], connect_address);
         assert (rc == 0);
     }
 
@@ -77,14 +80,16 @@ void test_fair_queue_in (void *ctx)
         free (str);
     }
 
-    rc = zmq_close (rep);
-    assert (rc == 0);
+    close_zero_linger (rep);
 
     for (size_t i = 0; i < N; ++i)
     {
-        rc = zmq_close (reqs[i]);
-        assert (rc == 0);
+        close_zero_linger (reqs[i]);
     }
+
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
+    assert (rc == 0);
 }
 
 void test_envelope (void *ctx)
@@ -92,13 +97,13 @@ void test_envelope (void *ctx)
     void *rep = zmq_socket (ctx, ZMQ_REP);
     assert (rep);
 
-    int rc = zmq_bind (rep, "inproc://b");
+    int rc = zmq_bind (rep, bind_address);
     assert (rc == 0);
 
     void *dealer = zmq_socket (ctx, ZMQ_DEALER);
     assert (dealer);
 
-    rc = zmq_connect (dealer, "inproc://b");
+    rc = zmq_connect (dealer, connect_address);
     assert (rc == 0);
 
     // minimal envelope
@@ -113,10 +118,11 @@ void test_envelope (void *ctx)
     s_send_seq (rep, "A", SEQ_END);
     s_recv_seq (dealer, "X", "Y", 0, "A", SEQ_END);
 
-    rc = zmq_close (rep);
-    assert (rc == 0);
+    close_zero_linger (rep);
+    close_zero_linger (dealer);
 
-    rc = zmq_close (dealer);
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
     assert (rc == 0);
 }
 
@@ -125,17 +131,25 @@ int main ()
     void *ctx = zmq_ctx_new ();
     assert (ctx);
 
-    // SHALL receive incoming messages from its peers using a fair-queuing
-    // strategy.
-    test_fair_queue_in (ctx);
+    const char *binds[] =    { "inproc://a", "tcp://*:5555" };
+    const char *connects[] = { "inproc://a", "tcp://localhost:5555" };
 
-    // For an incoming message:
-    // SHALL remove and store the address envelope, including the delimiter.
-    // SHALL pass the remaining data frames to its calling application.
-    // SHALL wait for a single reply message from its calling application.
-    // SHALL prepend the address envelope and delimiter.
-    // SHALL deliver this message back to the originating peer.
-    test_envelope (ctx);
+    for (int i = 0; i < 2; ++i) {
+        bind_address = binds[i];
+        connect_address = connects[i];
+
+        // SHALL receive incoming messages from its peers using a fair-queuing
+        // strategy.
+        test_fair_queue_in (ctx);
+
+        // For an incoming message:
+        // SHALL remove and store the address envelope, including the delimiter.
+        // SHALL pass the remaining data frames to its calling application.
+        // SHALL wait for a single reply message from its calling application.
+        // SHALL prepend the address envelope and delimiter.
+        // SHALL deliver this message back to the originating peer.
+        test_envelope (ctx);
+    }
 
     int rc = zmq_ctx_term (ctx);
     assert (rc == 0);
diff --git a/tests/test_spec_req.cpp b/tests/test_spec_req.cpp
index e6f9d43f..5d5eade0 100644
--- a/tests/test_spec_req.cpp
+++ b/tests/test_spec_req.cpp
@@ -20,12 +20,15 @@
 #include <stdio.h>
 #include "testutil.hpp"
 
+const char *bind_address = 0;
+const char *connect_address = 0;
+
 void test_round_robin_out (void *ctx)
 {
     void *req = zmq_socket (ctx, ZMQ_REQ);
     assert (req);
 
-    int rc = zmq_bind (req, "inproc://b");
+    int rc = zmq_bind (req, bind_address);
     assert (rc == 0);
 
     const size_t N = 5;
@@ -39,7 +42,7 @@ void test_round_robin_out (void *ctx)
         rc = zmq_setsockopt (rep[i], ZMQ_RCVTIMEO, &timeout, sizeof(int));
         assert (rc == 0);
 
-        rc = zmq_connect (rep[i], "inproc://b");
+        rc = zmq_connect (rep[i], connect_address);
         assert (rc == 0);
     }
 
@@ -52,14 +55,16 @@ void test_round_robin_out (void *ctx)
         s_recv_seq (req, "DEF", SEQ_END);
     }
 
-    rc = zmq_close (req);
-    assert (rc == 0);
+    close_zero_linger (req);
 
     for (size_t i = 0; i < N; ++i)
     {
-        rc = zmq_close (rep[i]);
-        assert (rc == 0);
+        close_zero_linger (rep[i]);
     }
+
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
+    assert (rc == 0);
 }
 
 void test_req_only_listens_to_current_peer (void *ctx)
@@ -70,7 +75,7 @@ void test_req_only_listens_to_current_peer (void *ctx)
     int rc = zmq_setsockopt(req, ZMQ_IDENTITY, "A", 2);
     assert (rc == 0);
 
-    rc = zmq_bind (req, "inproc://c");
+    rc = zmq_bind (req, bind_address);
     assert (rc == 0);
 
     const size_t N = 3;
@@ -88,7 +93,7 @@ void test_req_only_listens_to_current_peer (void *ctx)
         rc = zmq_setsockopt (router[i], ZMQ_ROUTER_MANDATORY, &enabled, sizeof(enabled));
         assert (rc == 0);
 
-        rc = zmq_connect (router[i], "inproc://c");
+        rc = zmq_connect (router[i], connect_address);
         assert (rc == 0);
     }
 
@@ -111,14 +116,16 @@ void test_req_only_listens_to_current_peer (void *ctx)
         s_recv_seq (req, "GOOD", SEQ_END);
     }
 
-    rc = zmq_close (req);
-    assert (rc == 0);
+    close_zero_linger (req);
 
     for (size_t i = 0; i < N; ++i)
     {
-        rc = zmq_close (router[i]);
-        assert (rc == 0);
+        close_zero_linger (router[i]);
     }
+
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
+    assert (rc == 0);
 }
 
 void test_req_message_format (void *ctx)
@@ -129,10 +136,10 @@ void test_req_message_format (void *ctx)
     void *router = zmq_socket (ctx, ZMQ_ROUTER);
     assert (router);
 
-    int rc = zmq_bind (req, "inproc://a");
+    int rc = zmq_bind (req, bind_address);
     assert (rc == 0);
 
-    rc = zmq_connect (router, "inproc://a");
+    rc = zmq_connect (router, connect_address);
     assert (rc == 0);
 
     // Send a multi-part request.
@@ -172,10 +179,11 @@ void test_req_message_format (void *ctx)
     rc = zmq_msg_close (&peer_id_msg);
     assert (rc == 0);
 
-    rc = zmq_close (req);
-    assert (rc == 0);
+    close_zero_linger (req);
+    close_zero_linger (router);
 
-    rc = zmq_close (router);
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
     assert (rc == 0);
 }
 
@@ -205,23 +213,31 @@ int main ()
     void *ctx = zmq_ctx_new ();
     assert (ctx);
 
-    // SHALL route outgoing messages to connected peers using a round-robin
-    // strategy.
-    test_round_robin_out (ctx);
+    const char *binds[] =    { "inproc://a", "tcp://*:5555" };
+    const char *connects[] = { "inproc://a", "tcp://localhost:5555" };
 
-    // The request and reply messages SHALL have this format on the wire:
-    // * A delimiter, consisting of an empty frame, added by the REQ socket.
-    // * One or more data frames, comprising the message visible to the
-    //   application.
-    test_req_message_format (ctx);
+    for (int i = 0; i < 2; ++i) {
+        bind_address = binds[i];
+        connect_address = connects[i];
 
-    // SHALL block on sending, or return a suitable error, when it has no connected peers.
-    test_block_on_send_no_peers (ctx);
+        // SHALL route outgoing messages to connected peers using a round-robin
+        // strategy.
+        test_round_robin_out (ctx);
 
-    // SHALL accept an incoming message only from the last peer that it sent a
-    // request to.
-    // SHALL discard silently any messages received from other peers.
-    test_req_only_listens_to_current_peer (ctx);
+        // The request and reply messages SHALL have this format on the wire:
+        // * A delimiter, consisting of an empty frame, added by the REQ socket.
+        // * One or more data frames, comprising the message visible to the
+        //   application.
+        test_req_message_format (ctx);
+
+        // SHALL block on sending, or return a suitable error, when it has no connected peers.
+        test_block_on_send_no_peers (ctx);
+
+        // SHALL accept an incoming message only from the last peer that it sent a
+        // request to.
+        // SHALL discard silently any messages received from other peers.
+        test_req_only_listens_to_current_peer (ctx);
+    }
 
     int rc = zmq_ctx_term (ctx);
     assert (rc == 0);
diff --git a/tests/test_spec_router.cpp b/tests/test_spec_router.cpp
index e5972e34..8de10d4c 100644
--- a/tests/test_spec_router.cpp
+++ b/tests/test_spec_router.cpp
@@ -21,6 +21,9 @@
 #include <stdlib.h>
 #include "testutil.hpp"
 
+const char *bind_address = 0;
+const char *connect_address = 0;
+
 void test_fair_queue_in (void *ctx)
 {
     void *receiver = zmq_socket (ctx, ZMQ_ROUTER);
@@ -30,7 +33,7 @@ void test_fair_queue_in (void *ctx)
     int rc = zmq_setsockopt (receiver, ZMQ_RCVTIMEO, &timeout, sizeof(int));
     assert (rc == 0);
 
-    rc = zmq_bind (receiver, "inproc://a");
+    rc = zmq_bind (receiver, bind_address);
     assert (rc == 0);
 
     const size_t N = 5;
@@ -49,7 +52,7 @@ void test_fair_queue_in (void *ctx)
         assert (rc == 0);
         free (str);
 
-        rc = zmq_connect (senders[i], "inproc://a");
+        rc = zmq_connect (senders[i], connect_address);
         assert (rc == 0);
     }
 
@@ -63,32 +66,43 @@ void test_fair_queue_in (void *ctx)
     s_send_seq (senders[0], "M", SEQ_END);
     s_recv_seq (receiver, "A", "M", SEQ_END);
 
+    int sum = 0;
+
     // send N requests
     for (size_t i = 0; i < N; ++i)
     {
         s_send_seq (senders[i], "M", SEQ_END);
+        sum += 'A' + i;
     }
 
+    assert (sum == N*'A' + N*(N-1)/2);
+
     // handle N requests
     for (size_t i = 0; i < N; ++i)
     {
-        char *str = strdup("A");
-        str[0] += i;
-        s_recv_seq (receiver, str, "M", SEQ_END);
-        free (str);
+        rc = zmq_msg_recv (&msg, receiver, 0);
+        assert (rc == 2);
+        const char *id = (const char *)zmq_msg_data (&msg);
+        sum -= id[0];
+
+        s_recv_seq (receiver, "M", SEQ_END);
     }
 
+    assert (sum == 0);
+
     rc = zmq_msg_close (&msg);
     assert (rc == 0);
 
-    rc = zmq_close (receiver);
-    assert (rc == 0);
+    close_zero_linger (receiver);
 
     for (size_t i = 0; i < N; ++i)
     {
-        rc = zmq_close (senders[i]);
-        assert (rc == 0);
+        close_zero_linger (senders[i]);
     }
+
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
+    assert (rc == 0);
 }
 
 void test_destroy_queue_on_disconnect (void *ctx)
@@ -100,7 +114,7 @@ void test_destroy_queue_on_disconnect (void *ctx)
     int rc = zmq_setsockopt (A, ZMQ_ROUTER_MANDATORY, &enabled, sizeof(enabled));
     assert (rc == 0);
 
-    rc = zmq_bind (A, "inproc://d");
+    rc = zmq_bind (A, bind_address);
     assert (rc == 0);
 
     void *B = zmq_socket (ctx, ZMQ_DEALER);
@@ -109,20 +123,26 @@ void test_destroy_queue_on_disconnect (void *ctx)
     rc = zmq_setsockopt (B, ZMQ_IDENTITY, "B", 2);
     assert (rc == 0);
 
-    rc = zmq_connect (B, "inproc://d");
+    rc = zmq_connect (B, connect_address);
+    assert (rc == 0);
+
+    // Wait for connection.
+    rc = zmq_poll (0, 0, 100);
     assert (rc == 0);
 
     // Send a message in both directions
     s_send_seq (A, "B", "ABC", SEQ_END);
     s_send_seq (B, "DEF", SEQ_END);
 
-    rc = zmq_disconnect (B, "inproc://d");
+    rc = zmq_disconnect (B, connect_address);
     assert (rc == 0);
 
     // Disconnect may take time and need command processing.
     zmq_pollitem_t poller[2] = { { A, 0, 0, 0 }, { B, 0, 0, 0 } };
     rc = zmq_poll (poller, 2, 100);
     assert (rc == 0);
+    rc = zmq_poll (poller, 2, 100);
+    assert (rc == 0);
 
     // No messages should be available, sending should fail.
     zmq_msg_t msg;
@@ -137,7 +157,7 @@ void test_destroy_queue_on_disconnect (void *ctx)
     assert (errno == EAGAIN);
 
     // After a reconnect of B, the messages should still be gone
-    rc = zmq_connect (B, "inproc://d");
+    rc = zmq_connect (B, connect_address);
     assert (rc == 0);
 
     rc = zmq_msg_recv (&msg, A, ZMQ_DONTWAIT);
@@ -151,10 +171,11 @@ void test_destroy_queue_on_disconnect (void *ctx)
     rc = zmq_msg_close (&msg);
     assert (rc == 0);
 
-    rc = zmq_close (A);
-    assert (rc == 0);
+    close_zero_linger (A);
+    close_zero_linger (B);
 
-    rc = zmq_close (B);
+    // Wait for disconnects.
+    rc = zmq_poll (0, 0, 100);
     assert (rc == 0);
 }
 
@@ -164,14 +185,22 @@ int main ()
     void *ctx = zmq_ctx_new ();
     assert (ctx);
 
-    // SHALL receive incoming messages from its peers using a fair-queuing
-    // strategy.
-    test_fair_queue_in (ctx);
+    const char *binds[] =    { "inproc://a", "tcp://*:5555" };
+    const char *connects[] = { "inproc://a", "tcp://localhost:5555" };
 
-    // SHALL create a double queue when a peer connects to it. If this peer
-    // disconnects, the ROUTER socket SHALL destroy its double queue and SHALL
-    // discard any messages it contains.
-    test_destroy_queue_on_disconnect (ctx);
+    for (int i = 0; i < 2; ++i) {
+        bind_address = binds[i];
+        connect_address = connects[i];
+
+        // SHALL receive incoming messages from its peers using a fair-queuing
+        // strategy.
+        test_fair_queue_in (ctx);
+
+        // SHALL create a double queue when a peer connects to it. If this peer
+        // disconnects, the ROUTER socket SHALL destroy its double queue and SHALL
+        // discard any messages it contains.
+        test_destroy_queue_on_disconnect (ctx);
+    }
 
     int rc = zmq_ctx_term (ctx);
     assert (rc == 0);
diff --git a/tests/testutil.hpp b/tests/testutil.hpp
index eb4b4e48..376d85d9 100644
--- a/tests/testutil.hpp
+++ b/tests/testutil.hpp
@@ -186,4 +186,15 @@ void s_recv_seq (void *socket, ...)
     zmq_msg_close (&msg);
 }
 
+
+// Sets a zero linger period on a socket and closes it.
+void close_zero_linger (void *socket)
+{
+    int linger = 0;
+    int rc = zmq_setsockopt (socket, ZMQ_LINGER, &linger, sizeof(linger));
+    assert (rc == 0);
+    rc = zmq_close (socket);
+    assert (rc == 0);
+}
+
 #endif