diff --git a/src/ws_encoder.cpp b/src/ws_encoder.cpp
index dfccb8bb..bc0b38c7 100644
--- a/src/ws_encoder.cpp
+++ b/src/ws_encoder.cpp
@@ -73,6 +73,9 @@ void zmq::ws_encoder_t::message_ready ()
     size_t size = in_progress ()->size ();
     if (_is_binary)
         size++;
+    //  TODO: create an opcode for subscribe/cancel
+    if (in_progress ()->is_subscribe () || in_progress ()->is_cancel ())
+        size++;
 
     if (size <= 125)
         _tmp_buf[offset++] |= static_cast<unsigned char> (size & 127);
@@ -93,6 +96,7 @@ void zmq::ws_encoder_t::message_ready ()
         offset += 4;
     }
 
+    int mask_index = 0;
     if (_is_binary) {
         //  Encode flags.
         unsigned char protocol_flags = 0;
@@ -102,9 +106,16 @@ void zmq::ws_encoder_t::message_ready ()
             protocol_flags |= ws_protocol_t::command_flag;
 
         _tmp_buf[offset++] =
-          _must_mask ? protocol_flags ^ _mask[0] : protocol_flags;
+          _must_mask ? protocol_flags ^ _mask[mask_index++] : protocol_flags;
     }
 
+    //  Encode the subscribe/cancel byte.
+    //  TODO: remove once there is an opcode for subscribe/cancel
+    if (in_progress ()->is_subscribe ())
+        _tmp_buf[offset++] = _must_mask ? 1 ^ _mask[mask_index++] : 1;
+    else if (in_progress ()->is_cancel ())
+        _tmp_buf[offset++] = _must_mask ? 0 ^ _mask[mask_index++] : 0;
+
     next_step (_tmp_buf, offset, &ws_encoder_t::size_ready, false);
 }
 
@@ -126,7 +137,12 @@ void zmq::ws_encoder_t::size_ready ()
             dest = static_cast<unsigned char *> (_masked_msg.data ());
         }
 
-        int mask_index = _is_binary ? 1 : 0;
+        int mask_index = 0;
+        if (_is_binary)
+            ++mask_index;
+        //  TODO: remove once there is an opcode for subscribe/cancel
+        if (in_progress ()->is_subscribe () || in_progress ()->is_cancel ())
+            ++mask_index;
         for (size_t i = 0; i < size; ++i, mask_index++)
             dest[i] = src[i] ^ _mask[mask_index % 4];
 
diff --git a/tests/test_ws_transport.cpp b/tests/test_ws_transport.cpp
index dbb6aed9..49b810fe 100644
--- a/tests/test_ws_transport.cpp
+++ b/tests/test_ws_transport.cpp
@@ -271,6 +271,33 @@ void test_mask_shared_msg ()
     test_context_socket_close (sb);
 }
 
+void test_pub_sub ()
+{
+    char connect_address[MAX_SOCKET_STRING];
+    size_t addr_length = sizeof (connect_address);
+    void *sb = test_context_socket (ZMQ_XPUB);
+    TEST_ASSERT_SUCCESS_ERRNO (zmq_bind (sb, "ws://127.0.0.1:*"));
+    TEST_ASSERT_SUCCESS_ERRNO (
+      zmq_getsockopt (sb, ZMQ_LAST_ENDPOINT, connect_address, &addr_length));
+
+    void *sc = test_context_socket (ZMQ_SUB);
+    TEST_ASSERT_SUCCESS_ERRNO (zmq_setsockopt (sc, ZMQ_SUBSCRIBE, "A", 1));
+    TEST_ASSERT_SUCCESS_ERRNO (zmq_setsockopt (sc, ZMQ_SUBSCRIBE, "B", 1));
+    TEST_ASSERT_SUCCESS_ERRNO (zmq_connect (sc, connect_address));
+
+    recv_string_expect_success (sb, "\1A", 0);
+    recv_string_expect_success (sb, "\1B", 0);
+
+    send_string_expect_success (sb, "A", 0);
+    send_string_expect_success (sb, "B", 0);
+
+    recv_string_expect_success (sc, "A", 0);
+    recv_string_expect_success (sc, "B", 0);
+
+    test_context_socket_close (sc);
+    test_context_socket_close (sb);
+}
+
 
 int main ()
 {
@@ -283,6 +310,7 @@ int main ()
     RUN_TEST (test_large_message);
     RUN_TEST (test_heartbeat);
     RUN_TEST (test_mask_shared_msg);
+    RUN_TEST (test_pub_sub);
 
     if (zmq_has ("curve"))
         RUN_TEST (test_curve);