--- a/browser/components/resistfingerprinting/test/browser/browser.ini
+++ b/browser/components/resistfingerprinting/test/browser/browser.ini
@@ -11,17 +11,18 @@ support-files =
 [browser_block_mozAddonManager.js]
 [browser_navigator.js]
 [browser_netInfo.js]
 [browser_performanceAPI.js]
 [browser_roundedWindow_dialogWindow.js]
 [browser_roundedWindow_newWindow.js]
 [browser_roundedWindow_open_max_inner.js]
 [browser_roundedWindow_open_max_outer.js]
-[browser_roundedWindow_open_mid.js]
+[browser_roundedWindow_open_mid_inner.js]
+[browser_roundedWindow_open_mid_outer.js]
 [browser_roundedWindow_open_min.js]
 [browser_roundedWindow_windowSetting_max_inner.js]
 [browser_roundedWindow_windowSetting_max_outer.js]
 [browser_roundedWindow_windowSetting_mid.js]
 [browser_roundedWindow_windowSetting_min_inner.js]
 [browser_roundedWindow_windowSetting_min_outer.js]
 [browser_timezone.js]
 [browser_bug1369357_site_specific_zoom_level.js]

deleted file mode 100644
--- a/browser/components/resistfingerprinting/test/browser/browser_roundedWindow_open_mid.js
+++ /dev/null
@@ -1,11 +0,0 @@
-/*
- * Bug 1330882 - A test case for opening new windows through window.open() as
- *   rounded size when fingerprinting resistance is enabled. This test is for
- *   middle values.
- */
-
-OpenTest.run([
-  {settingWidth: 600, settingHeight: 600, targetWidth: 600, targetHeight: 600},
-  {settingWidth: 599, settingHeight: 599, targetWidth: 600, targetHeight: 600},
-  {settingWidth: 401, settingHeight: 501, targetWidth: 600, targetHeight: 600}
-]);

new file mode 100644
--- /dev/null
+++ b/browser/components/resistfingerprinting/test/browser/browser_roundedWindow_open_mid_inner.js
@@ -0,0 +1,11 @@
+/*
+ * Bug 1330882 - A test case for opening new windows through window.open() as
+ *   rounded size when fingerprinting resistance is enabled. This test is for
+ *   middle values.
+ */
+
+OpenTest.run([
+  {settingWidth: 600, settingHeight: 600, targetWidth: 600, targetHeight: 600},
+  {settingWidth: 599, settingHeight: 599, targetWidth: 600, targetHeight: 600},
+  {settingWidth: 401, settingHeight: 501, targetWidth: 600, targetHeight: 600}
+], false);

new file mode 100644
--- /dev/null
+++ b/browser/components/resistfingerprinting/test/browser/browser_roundedWindow_open_mid_outer.js
@@ -0,0 +1,11 @@
+/*
+ * Bug 1330882 - A test case for opening new windows through window.open() as
+ *   rounded size when fingerprinting resistance is enabled. This test is for
+ *   middle values.
+ */
+
+OpenTest.run([
+  {settingWidth: 600, settingHeight: 600, targetWidth: 600, targetHeight: 600},
+  {settingWidth: 599, settingHeight: 599, targetWidth: 600, targetHeight: 600},
+  {settingWidth: 401, settingHeight: 501, targetWidth: 600, targetHeight: 600}
+], true);