--- a/browser/components/customizableui/CustomizeMode.jsm
+++ b/browser/components/customizableui/CustomizeMode.jsm
@@ -1389,19 +1389,26 @@ CustomizeMode.prototype = {
         tbb.addEventListener("blur", resetPreview);
         tbb.addEventListener("mouseout", resetPreview);
 
         return tbb;
       }
 
       let themes = [aDefaultTheme];
       let lwts = LightweightThemeManager.usedThemes;
+      let currentLwt = LightweightThemeManager.currentTheme;
+      let currentLwtIndex = lwts.indexOf(currentLwt);
+      if (currentLwtIndex > -1) {
+        // Make sure that the current lightweight theme
+        // is at the beginning of the array to avoid truncation
+        // in the next step.
+        lwts = lwts.splice(currentLwtIndex, 1).concat(lwts);
+      }
       if (lwts.length > RECENT_LWT_COUNT)
         lwts.length = RECENT_LWT_COUNT;
-      let currentLwt = LightweightThemeManager.currentTheme;
       for (let lwt of lwts) {
         lwt.isActive = !!currentLwt && (lwt.id == currentLwt.id);
         themes.push(lwt);
       }
 
       let footer = doc.getElementById("customization-lwtheme-menu-footer");
       let panel = footer.parentNode;
       let recommendedLabel = doc.getElementById("customization-lwtheme-menu-recommended");