diff --git a/devtools/client/debugger/src/components/WelcomeBox.css b/devtools/client/debugger/src/components/WelcomeBox.css
index c541273dec98..3ca2f2dd61a7 100644
--- a/devtools/client/debugger/src/components/WelcomeBox.css
+++ b/devtools/client/debugger/src/components/WelcomeBox.css
@@ -12,7 +12,7 @@
   text-align: center;
   background-color: var(--theme-toolbar-background);
   overflow: hidden;
-  font-weight: lighter;
+  font-weight: 300;
   z-index: 10;
   user-select: none;
 }