diff --git a/frontend_tests/node_tests/list_render.js b/frontend_tests/node_tests/list_render.js
index 5d97dd98e9..a183ed24df 100644
--- a/frontend_tests/node_tests/list_render.js
+++ b/frontend_tests/node_tests/list_render.js
@@ -6,9 +6,10 @@ zrequire('list_render');
 // that are either jQuery, Element, or just raw HTML
 // strings.  We initially test with raw strings.
 set_global('jQuery', 'stub');
-set_global('Element', function () {
+function Element() {
     return { };
-});
+}
+set_global('Element', Element);
 
 // We only need very simple jQuery wrappers for when the
 // "real" code wraps html or sets up click handlers.
diff --git a/frontend_tests/node_tests/markdown.js b/frontend_tests/node_tests/markdown.js
index 67c580c5a0..a763cc4c5b 100644
--- a/frontend_tests/node_tests/markdown.js
+++ b/frontend_tests/node_tests/markdown.js
@@ -44,9 +44,10 @@ set_global('page_params', {
     translate_emoticons: false,
 });
 
-set_global('Image', function () {
+function Image() {
     return {};
-});
+}
+set_global('Image', Image);
 emoji.initialize();
 
 const doc = "";
diff --git a/frontend_tests/node_tests/message_fetch.js b/frontend_tests/node_tests/message_fetch.js
index 6d1a32ca58..20ad12d099 100644
--- a/frontend_tests/node_tests/message_fetch.js
+++ b/frontend_tests/node_tests/message_fetch.js
@@ -5,7 +5,10 @@ zrequire('message_fetch');
 
 const noop = () => {};
 
-set_global('MessageListView', function () { return {}; });
+function MessageListView() {
+    return {};
+}
+set_global('MessageListView', MessageListView);
 
 zrequire('FetchStatus', 'js/fetch_status');
 zrequire('Filter', 'js/filter');
diff --git a/frontend_tests/node_tests/popovers.js b/frontend_tests/node_tests/popovers.js
index 02e7b24d59..e9e12bbce5 100644
--- a/frontend_tests/node_tests/popovers.js
+++ b/frontend_tests/node_tests/popovers.js
@@ -42,9 +42,10 @@ set_global('stream_popover', {
 
 set_global('stream_data', {});
 
-set_global('ClipboardJS', function (sel) {
+function ClipboardJS(sel) {
     assert.equal(sel, '.copy_link');
-});
+}
+set_global('ClipboardJS', ClipboardJS);
 
 const alice = {
     email: 'alice@example.com',
@@ -95,9 +96,7 @@ function make_image_stubber() {
         return image;
     }
 
-    set_global('Image', function () {
-        return stub_image();
-    });
+    set_global('Image', stub_image);
 
     return {
         get: (i) => images[i],
diff --git a/frontend_tests/node_tests/presence.js b/frontend_tests/node_tests/presence.js
index bb2e584e54..c1d508b22b 100644
--- a/frontend_tests/node_tests/presence.js
+++ b/frontend_tests/node_tests/presence.js
@@ -7,7 +7,10 @@ set_global('server_events', {});
 set_global('reload_state', {
     is_in_progress: return_false,
 });
-set_global('XDate', function (ms) { return {seconds: ms}; });
+function XDate(ms) {
+    return {seconds: ms};
+}
+set_global('XDate', XDate);
 
 const OFFLINE_THRESHOLD_SECS = 140;
 
diff --git a/frontend_tests/node_tests/settings_bots.js b/frontend_tests/node_tests/settings_bots.js
index cc6e9b6f79..1d8b83b3fb 100644
--- a/frontend_tests/node_tests/settings_bots.js
+++ b/frontend_tests/node_tests/settings_bots.js
@@ -24,9 +24,10 @@ zrequire('bot_data');
 zrequire('settings_bots');
 zrequire('people');
 
-set_global('ClipboardJS', function (sel) {
+function ClipboardJS(sel) {
     assert.equal(sel, '#copy_zuliprc');
-});
+}
+set_global('ClipboardJS', ClipboardJS);
 
 bot_data.initialize(bot_data_params);