diff --git a/packages/theme-chalk/src/input.scss b/packages/theme-chalk/src/input.scss
index e74dc56d1f..624f7edef5 100644
--- a/packages/theme-chalk/src/input.scss
+++ b/packages/theme-chalk/src/input.scss
@@ -189,6 +189,7 @@
     outline: none;
     border: none;
     background: none;
+    box-sizing: border-box;
 
     &:focus {
       outline: none;