diff --git a/browser/devtools/webide/content/webide.xul b/browser/devtools/webide/content/webide.xul
index a687036aaa4..3a9617050f0 100644
--- a/browser/devtools/webide/content/webide.xul
+++ b/browser/devtools/webide/content/webide.xul
@@ -196,11 +196,11 @@
       <iframe id="deck-panel-projecteditor" flex="1"/>
       <iframe id="deck-panel-addons" flex="1" src="addons.xhtml"/>
       <iframe id="deck-panel-prefs" flex="1" src="prefs.xhtml"/>
-      <iframe id="deck-panel-permissionstable" flex="1" src="permissionstable.xhtml"/>
-      <iframe id="deck-panel-runtimedetails" flex="1" src="runtimedetails.xhtml"/>
+      <iframe id="deck-panel-permissionstable" flex="1" lazysrc="permissionstable.xhtml"/>
+      <iframe id="deck-panel-runtimedetails" flex="1" lazysrc="runtimedetails.xhtml"/>
       <iframe id="deck-panel-monitor" flex="1" lazysrc="monitor.xhtml"/>
-      <iframe id="deck-panel-devicepreferences" flex="1" src="devicepreferences.xhtml"/>
-      <iframe id="deck-panel-devicesettings" flex="1" src="devicesettings.xhtml"/>
+      <iframe id="deck-panel-devicepreferences" flex="1" lazysrc="devicepreferences.xhtml"/>
+      <iframe id="deck-panel-devicesettings" flex="1" lazysrc="devicesettings.xhtml"/>
     </deck>
     <splitter hidden="true" class="devtools-horizontal-splitter" orient="vertical"/>
     <!-- toolbox iframe will be inserted here -->
diff --git a/browser/devtools/webide/test/test_device_preferences.html b/browser/devtools/webide/test/test_device_preferences.html
index 131386516bc..0bb4e5f0155 100644
--- a/browser/devtools/webide/test/test_device_preferences.html
+++ b/browser/devtools/webide/test/test_device_preferences.html
@@ -30,14 +30,10 @@
 
           let prefIframe = win.document.querySelector("#deck-panel-devicepreferences");
 
-          yield documentIsLoaded(prefIframe.contentWindow.document);
-
           win.AppManager.update("runtimelist");
 
           yield connectToLocalRuntime(win);
 
-          yield nextTick();
-
           let prefs = win.document.querySelector("#cmd_showDevicePrefs");
 
           ok(!prefs.hasAttribute("disabled"), "device prefs cmd enabled");
@@ -47,9 +43,14 @@
           win.Cmds.showDevicePrefs();
           is(deck.selectedPanel, prefIframe, "device preferences iframe selected");
 
-          yield prefIframe.contentWindow.getAllPrefs;
           yield nextTick();
 
+          yield documentIsLoaded(prefIframe.contentWindow.document);
+
+          yield nextTick();
+
+          yield prefIframe.contentWindow.getAllPrefs;
+
           setDocument(prefIframe);
 
           let fields = doc.querySelectorAll(".editable");
diff --git a/browser/devtools/webide/test/test_device_settings.html b/browser/devtools/webide/test/test_device_settings.html
index b93166c7128..96a4356fa3c 100644
--- a/browser/devtools/webide/test/test_device_settings.html
+++ b/browser/devtools/webide/test/test_device_settings.html
@@ -34,14 +34,10 @@
 
           let settingIframe = win.document.querySelector("#deck-panel-devicesettings");
 
-          yield documentIsLoaded(settingIframe.contentWindow.document);
-
           win.AppManager.update("runtimelist");
 
           yield connectToLocalRuntime(win);
 
-          yield nextTick();
-
           let settings = win.document.querySelector("#cmd_showSettings");
 
           ok(!settings.hasAttribute("disabled"), "device settings cmd enabled");
@@ -51,9 +47,14 @@
           win.Cmds.showSettings();
           is(deck.selectedPanel, settingIframe, "device settings iframe selected");
 
-          yield settingIframe.contentWindow.getAllSettings;
           yield nextTick();
 
+          yield documentIsLoaded(settingIframe.contentWindow.document);
+
+          yield nextTick();
+
+          yield settingIframe.contentWindow.getAllSettings;
+
           setDocument(settingIframe);
 
           let fields = doc.querySelectorAll(".editable");
diff --git a/browser/devtools/webide/test/test_deviceinfo.html b/browser/devtools/webide/test/test_deviceinfo.html
index f6309b1d236..b4643c5e28c 100644
--- a/browser/devtools/webide/test/test_deviceinfo.html
+++ b/browser/devtools/webide/test/test_deviceinfo.html
@@ -31,9 +31,6 @@
           let permIframe = win.document.querySelector("#deck-panel-permissionstable");
           let infoIframe = win.document.querySelector("#deck-panel-runtimedetails");
 
-          yield documentIsLoaded(permIframe.contentWindow.document);
-          yield documentIsLoaded(infoIframe.contentWindow.document);
-
           yield connectToLocalRuntime(win);
 
           yield nextTick();
@@ -49,10 +46,14 @@
           win.Cmds.showRuntimeDetails();
           is(deck.selectedPanel, infoIframe, "info iframe selected");
 
-          yield infoIframe.contentWindow.getDescriptionPromise;
+          yield nextTick();
+
+          yield documentIsLoaded(infoIframe.contentWindow.document);
 
           yield nextTick();
 
+          yield infoIframe.contentWindow.getDescriptionPromise;
+
           // device info and permissions content is checked in other tests
           // We just test one value to make sure we get something
 
@@ -72,6 +73,12 @@
           win.Cmds.showPermissionsTable();
           is(deck.selectedPanel, permIframe, "permission iframe selected");
 
+          yield nextTick();
+
+          yield documentIsLoaded(permIframe.contentWindow.document);
+
+          yield nextTick();
+
           yield permIframe.contentWindow.getRawPermissionsTablePromise;
 
           yield nextTick();