diff --git a/src/BaseInput.tsx b/src/BaseInput.tsx
index a8253a1..bf8fcb7 100644
--- a/src/BaseInput.tsx
+++ b/src/BaseInput.tsx
@@ -55,10 +55,11 @@ const BaseInput = React.forwardRef<HolderRef, BaseInputProps>((props, ref) => {
 
   let element: ReactElement = cloneElement(inputElement as ReactElement<any>, {
     value,
-    className: clsx(
-      (inputElement as ReactElement<any>).props?.className,
-      !hasAffix && classNames?.variant,
-    ),
+    className:
+      clsx(
+        (inputElement as ReactElement<any>).props?.className,
+        !hasAffix && classNames?.variant,
+      ) || null,
   });
 
   // ======================== Ref ======================== //
@@ -193,7 +194,8 @@ const BaseInput = React.forwardRef<HolderRef, BaseInputProps>((props, ref) => {
 
   // `className` and `style` are always on the root element
   return React.cloneElement(element as ReactElement<any>, {
-    className: clsx((element as ReactElement<any>).props?.className, className),
+    className:
+      clsx((element as ReactElement<any>).props?.className, className) || null,
     style: {
       ...(element as ReactElement<any>).props?.style,
       ...style,