diff --git a/app/src/cc/arduino/view/preferences/Preferences.form b/app/src/cc/arduino/view/preferences/Preferences.form
index 797e9d57d..2383e6fa7 100644
--- a/app/src/cc/arduino/view/preferences/Preferences.form
+++ b/app/src/cc/arduino/view/preferences/Preferences.form
@@ -366,6 +366,9 @@
                     <Property name="icon" type="javax.swing.Icon" editor="org.netbeans.modules.form.RADConnectionPropertyEditor">
                       <Connection code="new ImageIcon(Theme.getThemeImage(&quot;newwindow&quot;, this, Theme.scale(16), Theme.scale(14)))" type="code"/>
                     </Property>
+                    <Property name="toolTipText" type="java.lang.String" editor="org.netbeans.modules.form.RADConnectionPropertyEditor">
+                      <Connection code="tr(&quot;Enter additional URLs, one for each row&quot;)" type="code"/>
+                    </Property>
                     <Property name="margin" type="java.awt.Insets" editor="org.netbeans.beaninfo.editors.InsetsEditor">
                       <Insets value="[1, 1, 1, 1]"/>
                     </Property>
diff --git a/app/src/cc/arduino/view/preferences/Preferences.java b/app/src/cc/arduino/view/preferences/Preferences.java
index 005d2f83e..065052315 100644
--- a/app/src/cc/arduino/view/preferences/Preferences.java
+++ b/app/src/cc/arduino/view/preferences/Preferences.java
@@ -218,6 +218,7 @@ public class Preferences extends javax.swing.JDialog {
     additionalBoardsManagerField.setToolTipText(tr("Enter a comma separated list of urls"));
 
     extendedAdditionalUrlFieldWindow.setIcon(new ImageIcon(Theme.getThemeImage("newwindow", this, Theme.scale(16), Theme.scale(14))));
+    extendedAdditionalUrlFieldWindow.setToolTipText(tr("Enter additional URLs, one for each row"));
     extendedAdditionalUrlFieldWindow.setMargin(new java.awt.Insets(1, 1, 1, 1));
     extendedAdditionalUrlFieldWindow.addActionListener(new java.awt.event.ActionListener() {
       public void actionPerformed(java.awt.event.ActionEvent evt) {