diff --git a/browser/devtools/webide/themes/webide.css b/browser/devtools/webide/themes/webide.css
index 4410ddbe6622..09c7544a5e37 100644
--- a/browser/devtools/webide/themes/webide.css
+++ b/browser/devtools/webide/themes/webide.css
@@ -67,6 +67,8 @@ window.busy-determined #action-busy-undetermined {
 
 #project-panel-button {
   -moz-box-pack: start;
+  width: 150px;
+  max-width: 150px;
 }
 
 #project-panel-button > .panel-button-image {
@@ -86,6 +88,7 @@ window.busy-determined #action-busy-undetermined {
 }
 
 #project-panel-button > .panel-button-label {
+  width: 150px;
   max-width: 150px;
 }