diff --git a/crates/wasm-bindgen-macro/src/ast.rs b/crates/wasm-bindgen-macro/src/ast.rs
index 1af1057d..6396f6f5 100644
--- a/crates/wasm-bindgen-macro/src/ast.rs
+++ b/crates/wasm-bindgen-macro/src/ast.rs
@@ -139,7 +139,6 @@ impl Function {
         }
 
         let arguments = decl.inputs.iter()
-            .map(|i| i.into_item())
             .map(|arg| {
                 match *arg {
                     syn::FnArg::Captured(ref c) => c,
@@ -336,7 +335,6 @@ impl Struct {
 
         let mut mutable = None;
         let arguments = method.sig.decl.inputs.iter()
-            .map(|i| i.into_item())
             .filter_map(|arg| {
                 match *arg {
                     syn::FnArg::Captured(ref c) => Some(c),
diff --git a/crates/wasm-bindgen-macro/src/lib.rs b/crates/wasm-bindgen-macro/src/lib.rs
index 0bafa39f..7c545332 100644
--- a/crates/wasm-bindgen-macro/src/lib.rs
+++ b/crates/wasm-bindgen-macro/src/lib.rs
@@ -429,7 +429,6 @@ fn bindgen_import(import: &ast::Import, tokens: &mut Tokens) {
 
     let names = import.decl.inputs
         .iter()
-        .map(|i| i.into_item())
         .map(|arg| {
             match *arg {
                 syn::FnArg::Captured(ref c) => c,