diff --git a/src/components/forms/TextField.tsx b/src/components/forms/TextField.tsx
index daa85c23ef..b42f9d56e3 100644
--- a/src/components/forms/TextField.tsx
+++ b/src/components/forms/TextField.tsx
@@ -96,6 +96,8 @@ export function Root({children, isInvalid = false, style}: RootProps) {
           a.relative,
           a.w_full,
           a.px_md,
+          // Contain the input's z-index so it cannot paint over nearby overlays.
+          {zIndex: 0},
           style,
         ]}
         {...web({