diff --git a/devtools/client/application/test/browser/browser_application_panel_manifest-display.js b/devtools/client/application/test/browser/browser_application_panel_manifest-display.js
index 4161c79d3f49..b03e93e5e6b1 100644
--- a/devtools/client/application/test/browser/browser_application_panel_manifest-display.js
+++ b/devtools/client/application/test/browser/browser_application_panel_manifest-display.js
@@ -19,7 +19,7 @@ add_task(async function() {
 
   info("Waiting for the manifest to be displayed");
   await waitUntil(() => doc.querySelector(".js-manifest") !== null);
-  ok("Manifest is being displayed");
+  ok(true, "Manifest is being displayed");
 
   // assert manifest members are being properly displayed
   checkManifestMember(doc, "name", "Foo");
@@ -49,7 +49,7 @@ add_task(async function() {
 
   info("Waiting for the manifest to be displayed");
   await waitUntil(() => doc.querySelector(".js-manifest") !== null);
-  ok("Manifest is being displayed");
+  ok(true, "Manifest is being displayed");
 
   // assert manifest members are being properly displayed
   checkManifestMember(doc, "name", "Foo");
@@ -80,7 +80,7 @@ add_task(async function() {
 
   info("Waiting for the manifest to be displayed");
   await waitUntil(() => doc.querySelector(".js-manifest") !== null);
-  ok("Manifest is being displayed");
+  ok(true, "Manifest is being displayed");
 
   const issuesEl = doc.querySelector(".js-manifest-issues");
   ok(issuesEl !== null, "Validation issues are displayed");
diff --git a/devtools/client/debugger/test/mochitest/browser_dbg-bfcache.js b/devtools/client/debugger/test/mochitest/browser_dbg-bfcache.js
index 0b067db0f9dd..3150508cef78 100644
--- a/devtools/client/debugger/test/mochitest/browser_dbg-bfcache.js
+++ b/devtools/client/debugger/test/mochitest/browser_dbg-bfcache.js
@@ -12,5 +12,5 @@ add_task(async function() {
   await waitForSources(dbg, "doc-bfcache1.html");
   invokeInTab("goForward");
   await waitForSources(dbg, "doc-bfcache2.html");
-  ok("Found sources after BFCache navigations");
+  ok(true, "Found sources after BFCache navigations");
 });
diff --git a/devtools/client/debugger/test/mochitest/browser_dbg-breakpoint-skipping-console.js b/devtools/client/debugger/test/mochitest/browser_dbg-breakpoint-skipping-console.js
index 462a22b1134f..65c6bea4f2c9 100644
--- a/devtools/client/debugger/test/mochitest/browser_dbg-breakpoint-skipping-console.js
+++ b/devtools/client/debugger/test/mochitest/browser_dbg-breakpoint-skipping-console.js
@@ -14,5 +14,5 @@ add_task(async function() {
   toolbox.target.navigateTo({ url: "doc-debugger-statements.html" });
 
   await hasConsoleMessage({ toolbox }, 'done!')
-  ok('We reached the end');
+  ok(true, 'We reached the end');
 });
diff --git a/devtools/client/debugger/test/mochitest/browser_dbg-breakpoints-actions.js b/devtools/client/debugger/test/mochitest/browser_dbg-breakpoints-actions.js
index e7140355701e..d10f56892d8a 100644
--- a/devtools/client/debugger/test/mochitest/browser_dbg-breakpoints-actions.js
+++ b/devtools/client/debugger/test/mochitest/browser_dbg-breakpoints-actions.js
@@ -19,7 +19,7 @@ add_task(async function() {
   selectContextMenuItem(dbg, selectors.breakpointContextMenu.remove);
 
   await waitForState(dbg, state => dbg.selectors.getBreakpointCount() === 0);
-  ok("successfully removed the breakpoint");
+  ok(true, "successfully removed the breakpoint");
 });
 
 // Tests "disable others", "enable others" and "remove others" context actions
@@ -47,7 +47,7 @@ add_task(async function() {
       .every(bp => (bp.location.line !== 4) === bp.disabled)
   );
   await dispatched;
-  ok("breakpoint at 4 is the only enabled breakpoint");
+  ok(true, "breakpoint at 4 is the only enabled breakpoint");
 
   openFirstBreakpointContextMenu(dbg);
   // select "Disable All"
@@ -57,7 +57,7 @@ add_task(async function() {
     dbg.selectors.getBreakpointsList().every(bp => bp.disabled)
   );
   await dispatched;
-  ok("all breakpoints are disabled");
+  ok(true, "all breakpoints are disabled");
 
   openFirstBreakpointContextMenu(dbg);
   // select "Enable Others"
@@ -69,7 +69,7 @@ add_task(async function() {
       .every(bp => (bp.location.line === 4) === bp.disabled)
   );
   await dispatched;
-  ok("all breakpoints except line 1 are enabled");
+  ok(true, "all breakpoints except line 1 are enabled");
 
   openFirstBreakpointContextMenu(dbg);
   // select "Remove Others"
@@ -82,5 +82,5 @@ add_task(async function() {
       dbg.selectors.getBreakpointsList()[0].location.line === 4
   );
   await dispatched;
-  ok("remaining breakpoint should be on line 4");
+  ok(true, "remaining breakpoint should be on line 4");
 });
diff --git a/devtools/client/debugger/test/mochitest/browser_dbg-remember-expanded-scopes.js b/devtools/client/debugger/test/mochitest/browser_dbg-remember-expanded-scopes.js
index cd20fa01127b..1273d9f3cf55 100644
--- a/devtools/client/debugger/test/mochitest/browser_dbg-remember-expanded-scopes.js
+++ b/devtools/client/debugger/test/mochitest/browser_dbg-remember-expanded-scopes.js
@@ -37,5 +37,5 @@ add_task(async function() {
   await waitForPaused(dbg);
 
   await waitUntil(() => findNode(dbg, "innerData"));
-  ok("Inner object data automatically expanded after stepping");
+  ok(true, "Inner object data automatically expanded after stepping");
 });
diff --git a/devtools/client/inspector/test/browser_inspector_initialization.js b/devtools/client/inspector/test/browser_inspector_initialization.js
index 53aeb0f81cc6..2d170634b1d7 100644
--- a/devtools/client/inspector/test/browser_inspector_initialization.js
+++ b/devtools/client/inspector/test/browser_inspector_initialization.js
@@ -57,7 +57,7 @@ async function testToolboxInitialization(testActor, tab) {
   info("Destroying toolbox");
   await toolbox.destroy();
 
-  ok("true", "'destroyed' notification received.");
+  ok(true, "'destroyed' notification received.");
   ok(!gDevTools.getToolbox(target), "Toolbox destroyed.");
 }
 
diff --git a/devtools/client/inspector/test/browser_inspector_reload_xul.js b/devtools/client/inspector/test/browser_inspector_reload_xul.js
index 7df18eab1af8..4650885aaad0 100644
--- a/devtools/client/inspector/test/browser_inspector_reload_xul.js
+++ b/devtools/client/inspector/test/browser_inspector_reload_xul.js
@@ -41,7 +41,7 @@ async function testToolboxInitialization(tab, inspector, toolbox) {
   info("Destroying toolbox.");
   await toolbox.destroy();
 
-  ok("true", "'destroyed' notification received.");
+  ok(true, "'destroyed' notification received.");
   ok(!gDevTools.getToolbox(target), "Toolbox destroyed.");
 }
 
diff --git a/devtools/client/performance/test/browser_perf-refresh.js b/devtools/client/performance/test/browser_perf-refresh.js
index 33883438e9a2..bea41c5fc69e 100644
--- a/devtools/client/performance/test/browser_perf-refresh.js
+++ b/devtools/client/performance/test/browser_perf-refresh.js
@@ -40,7 +40,7 @@ add_task(async function() {
   );
 
   await waitUntil(() => recording.getMarkers().length > markersLength);
-  ok("Markers continue after reload.");
+  ok(true, "Markers continue after reload.");
 
   await stopRecording(panel);
   await teardownToolboxAndRemoveTab(panel);
diff --git a/devtools/client/webconsole/test/browser/browser_jsterm_editor.js b/devtools/client/webconsole/test/browser/browser_jsterm_editor.js
index 4f6a1a9b2bb5..4ea70a852f6f 100644
--- a/devtools/client/webconsole/test/browser/browser_jsterm_editor.js
+++ b/devtools/client/webconsole/test/browser/browser_jsterm_editor.js
@@ -41,7 +41,7 @@ add_task(async function() {
   await toggleLayout(hud);
   getInlineOpenEditorButton(hud).click();
   await waitFor(() => isEditorModeEnabled(hud));
-  ok("Editor is open when clicking on the button");
+  ok(true, "Editor is open when clicking on the button");
 });
 
 function getInlineOpenEditorButton(hud) {
diff --git a/devtools/client/webconsole/test/browser/browser_webconsole_observer_notifications.js b/devtools/client/webconsole/test/browser/browser_webconsole_observer_notifications.js
index a78b79c6ef45..44b8736d5200 100644
--- a/devtools/client/webconsole/test/browser/browser_webconsole_observer_notifications.js
+++ b/devtools/client/webconsole/test/browser/browser_webconsole_observer_notifications.js
@@ -18,7 +18,7 @@ add_task(async function() {
   await closeTabAndToolbox(gBrowser.selectedTab);
   await waitFor(() => destroyed);
 
-  ok("We received both created and destroyed events");
+  ok(true, "We received both created and destroyed events");
 });
 
 function setupObserver() {