diff --git a/modules/web/src/com/haulmont/cuba/web/WebWindowManager.java b/modules/web/src/com/haulmont/cuba/web/WebWindowManager.java
index af6011ef23..eee327feb7 100644
--- a/modules/web/src/com/haulmont/cuba/web/WebWindowManager.java
+++ b/modules/web/src/com/haulmont/cuba/web/WebWindowManager.java
@@ -1122,7 +1122,7 @@ public class WebWindowManager extends WindowManager {
             }
 
             if (action instanceof AbstractAction && ((AbstractAction)action).isPrimary()) {
-                button.addStyleName("primary");
+                button.addStyleName("cuba-primary-action");
                 button.focus();
             }