diff --git a/serde/src/private/de.rs b/serde/src/private/de.rs
index c30cc7373..f8ce6797f 100644
--- a/serde/src/private/de.rs
+++ b/serde/src/private/de.rs
@@ -529,9 +529,10 @@ mod content {
         where
             V: EnumAccess<'de>,
         {
+            #[allow(unused_imports)]
             use crate::de::VariantAccess;
             let (key, data) = tri!(visitor.variant::<String>());
-            Ok(Content::Map(vec![(
+            Ok(Content::Map(alloc::vec![(
                 Content::String(key),
                 tri!(data.newtype_variant::<Self::Value>()),
             )]))