diff --git a/browser/base/content/tabbrowser.xml b/browser/base/content/tabbrowser.xml
index 074f3b56e8fd..8679b48f40db 100644
--- a/browser/base/content/tabbrowser.xml
+++ b/browser/base/content/tabbrowser.xml
@@ -184,6 +184,7 @@
           this.moveTabTo(aTab, this._numPinnedTabs);
           aTab.setAttribute("pinned", "true");
           this.tabContainer._positionPinnedTabs();
+          this.tabContainer.adjustTabstrip();
         ]]></body>
       </method>
 
@@ -198,6 +199,7 @@
           aTab.removeAttribute("pinned");
           aTab.style.MozMarginStart = "";
           this.tabContainer._positionPinnedTabs();
+          this.tabContainer.adjustTabstrip();
         ]]></body>
       </method>