diff --git a/platform/lang-impl/src/com/intellij/codeInsight/documentation/DocumentationComponent.java b/platform/lang-impl/src/com/intellij/codeInsight/documentation/DocumentationComponent.java
index ad93627383ed..60d6788c32e3 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/documentation/DocumentationComponent.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/documentation/DocumentationComponent.java
@@ -346,6 +346,7 @@ public class DocumentationComponent extends JPanel implements Disposable, DataPr
     myFontSizeSlider.setSnapToTicks(true);
     UIUtil.setSliderIsFilled(myFontSizeSlider, true);
     result.add(myFontSizeSlider);
+    result.setBorder(BorderFactory.createLineBorder(UIUtil.getBorderColor(), 1));
 
     myFontSizeSlider.addChangeListener(new ChangeListener() {
       @Override