diff --git a/src/jsMain/kotlin/dev/inmo/jsuikit/modifiers/UIKitForm.kt b/src/jsMain/kotlin/dev/inmo/jsuikit/modifiers/UIKitForm.kt
index 4c10841..96d5b91 100644
--- a/src/jsMain/kotlin/dev/inmo/jsuikit/modifiers/UIKitForm.kt
+++ b/src/jsMain/kotlin/dev/inmo/jsuikit/modifiers/UIKitForm.kt
@@ -49,6 +49,7 @@ sealed class UIKitForm(
     class Custom(
         target: String? = null
     ) : UIKitForm(
+        "uk-form-custom",
         otherAttrs = mapOf(
             buildAttribute("uk-form-custom") {
                 "target" to target