diff --git a/src/ext.rs b/src/ext.rs
index 4801b9afa6..0e257a61b7 100644
--- a/src/ext.rs
+++ b/src/ext.rs
@@ -1,6 +1,7 @@
 //! HTTP extensions.
 
 use bytes::Bytes;
+#[cfg(any(feature = "http1", feature = "ffi"))]
 use http::header::HeaderName;
 #[cfg(feature = "http1")]
 use http::header::{IntoHeaderName, ValueIter};