diff --git a/devtools/client/inspector/rules/test/browser_rules_inactive_css_display-justify.js b/devtools/client/inspector/rules/test/browser_rules_inactive_css_display-justify.js
index 490bd0f1aa9c..1e787db14c12 100644
--- a/devtools/client/inspector/rules/test/browser_rules_inactive_css_display-justify.js
+++ b/devtools/client/inspector/rules/test/browser_rules_inactive_css_display-justify.js
@@ -29,7 +29,7 @@ add_task(async function() {
   const displayGrid = { display: "grid" };
 
   info("Enable display:flex and check that justify-content becomes active");
-  checkDeclarationIsInactive(view, 1, justifyContent);
+  await checkDeclarationIsInactive(view, 1, justifyContent);
   await toggleDeclaration(view, 1, displayFlex);
   checkDeclarationIsActive(view, 1, justifyContent);
 
@@ -37,7 +37,7 @@ add_task(async function() {
     "Rename justify-content to justify-items and check that it becomes inactive"
   );
   await updateDeclaration(view, 1, justifyContent, justifyItems);
-  checkDeclarationIsInactive(view, 1, justifyItems);
+  await checkDeclarationIsInactive(view, 1, justifyItems);
 
   info(
     "Rename display:flex to display:grid and check that justify-items becomes active"
diff --git a/devtools/client/inspector/rules/test/browser_rules_inactive_css_split-condition.js b/devtools/client/inspector/rules/test/browser_rules_inactive_css_split-condition.js
index bfb25b275471..514dee4231bb 100644
--- a/devtools/client/inspector/rules/test/browser_rules_inactive_css_split-condition.js
+++ b/devtools/client/inspector/rules/test/browser_rules_inactive_css_split-condition.js
@@ -27,5 +27,5 @@ add_task(async function() {
 
   checkDeclarationIsActive(view, 1, { gap: "1em" });
   await toggleDeclaration(view, 2, { display: "grid" });
-  checkDeclarationIsInactive(view, 1, { gap: "1em" });
+  await checkDeclarationIsInactive(view, 1, { gap: "1em" });
 });