diff --git a/humbug/urls.py b/humbug/urls.py
index bb9c04c686..abe02194c5 100644
--- a/humbug/urls.py
+++ b/humbug/urls.py
@@ -22,7 +22,7 @@ urlpatterns = patterns('',
     url(r'^json/subscriptions/list$', 'zephyr.views.json_list_subscriptions', name='json_list_subscriptions'),
     url(r'^json/subscriptions/remove$', 'zephyr.views.json_remove_subscription', name='json_remove_subscription'),
     url(r'^json/subscriptions/add$', 'zephyr.views.json_add_subscription', name='json_add_subscription'),
-    url(r'^json/subscriptions/exists/(?P<stream>.*)$', 'zephyr.views.json_stream_exists', name='json_stream_exists'),
+    url(r'^json/subscriptions/exists$', 'zephyr.views.json_stream_exists', name='json_stream_exists'),
 
     # These are json format views used by the API.  They require an API key.
     url(r'^api/v1/get_messages$', 'zephyr.views.api_get_messages', name='api_get_messages'),
diff --git a/zephyr/static/js/compose.js b/zephyr/static/js/compose.js
index 4e479f63a0..69ada5211e 100644
--- a/zephyr/static/js/compose.js
+++ b/zephyr/static/js/compose.js
@@ -102,7 +102,8 @@ function check_stream_for_send(stream_name) {
     var okay = true;
     $.ajax({
         type: "POST",
-        url: "/json/subscriptions/exists/" + stream_name,
+        url: "/json/subscriptions/exists",
+        data: {'stream': stream_name},
         async: false,
         success: function (data) {
             if (data.exists === "False") {
diff --git a/zephyr/tests.py b/zephyr/tests.py
index f77447dd66..e0bf9f6c8b 100644
--- a/zephyr/tests.py
+++ b/zephyr/tests.py
@@ -123,7 +123,7 @@ class PublicURLTest(TestCase):
                       "/json/settings/change/",
                       "/json/subscriptions/list",
                       "/json/subscriptions/remove",
-                      "/json/subscriptions/exists/test",
+                      "/json/subscriptions/exists",
                       "/json/subscriptions/add"],
                 }
         for status_code, url_set in urls.iteritems():
diff --git a/zephyr/views.py b/zephyr/views.py
index 2cbb3cd8d4..9929f0dbb3 100644
--- a/zephyr/views.py
+++ b/zephyr/views.py
@@ -591,7 +591,10 @@ def json_change_settings(request):
     return json_success(result)
 
 @login_required_json_view
-def json_stream_exists(request, stream):
+def json_stream_exists(request):
+    if "stream" not in request.POST:
+        return json_error("Missing stream argument.")
+    stream = request.POST.get("stream")
     if not valid_stream_name(stream):
         return json_error("Invalid characters in stream name")
     exists = bool(get_stream(stream, UserProfile.objects.get(user=request.user).realm))