diff --git a/frontend_tests/node_tests/compose.js b/frontend_tests/node_tests/compose.js
index 48d2bcd26c..5f66f88d8e 100644
--- a/frontend_tests/node_tests/compose.js
+++ b/frontend_tests/node_tests/compose.js
@@ -1,8 +1,6 @@
 set_global('bridge', false);
 
-set_global('blueslip', global.make_zblueslip({
-    error: false, // Ignore errors. We only check for warnings in this module.
-}));
+set_global('blueslip', global.make_zblueslip({}));
 
 const noop = function () {};
 
@@ -876,6 +874,7 @@ function test_raw_file_drop(raw_drop_func) {
 run_test('warn_if_private_stream_is_linked', () => {
     stream_data.add_sub(compose_state.stream_name(), {
         subscribers: new LazySet([1, 2]),
+        stream_id: 99,
     });
 
     let denmark = {
@@ -1660,7 +1659,15 @@ run_test('create_message_object', () => {
 
 
     let message = compose.create_message_object();
-    assert.equal(message.to, 'social');
+    assert.equal(message.to, sub.stream_id);
+    assert.equal(message.topic, 'lunch');
+    assert.equal(message.content, 'burrito');
+
+    blueslip.set_test_data('error', 'Trying to send message with bad stream name: BOGUS STREAM');
+
+    page['#stream_message_recipient_stream'] = 'BOGUS STREAM';
+    message = compose.create_message_object();
+    assert.equal(message.to, 'BOGUS STREAM');
     assert.equal(message.topic, 'lunch');
     assert.equal(message.content, 'burrito');
 
diff --git a/static/js/compose.js b/static/js/compose.js
index 8864c07336..ebdaa44576 100644
--- a/static/js/compose.js
+++ b/static/js/compose.js
@@ -195,11 +195,19 @@ function create_message_object() {
 
     } else {
         const stream_name = compose_state.stream_name();
-        message.to = stream_name;
         message.stream = stream_name;
         const sub = stream_data.get_sub(stream_name);
         if (sub) {
             message.stream_id = sub.stream_id;
+            message.to = sub.stream_id;
+        } else {
+            // We should be validating streams in calling code.  We'll
+            // try to fall back to stream_name here just in case the
+            // user started composing to the old stream name and
+            // manually entered the stream name, and it got past
+            // validation. We should try to kill this code off eventually.
+            blueslip.error('Trying to send message with bad stream name: ' + stream_name);
+            message.to = stream_name;
         }
         util.set_message_topic(message, topic);
     }