diff --git a/src/librustc/hir/mod.rs b/src/librustc/hir/mod.rs
index b99a4a03de9..5e41c51abd9 100644
--- a/src/librustc/hir/mod.rs
+++ b/src/librustc/hir/mod.rs
@@ -2024,17 +2024,6 @@ pub struct FnHeader {
     pub abi: Abi,
 }
 
-impl Default for FnHeader {
-    fn default() -> FnHeader {
-        FnHeader {
-            unsafety: Unsafety::Normal,
-            constness: Constness::NotConst,
-            asyncness: IsAsync::NotAsync,
-            abi: Abi::Rust,
-        }
-    }
-}
-
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum Item_ {
     /// An `extern crate` item, with optional *original* crate name if the crate was renamed.
diff --git a/src/librustc/hir/print.rs b/src/librustc/hir/print.rs
index 4db2247103e..51a7504efcf 100644
--- a/src/librustc/hir/print.rs
+++ b/src/librustc/hir/print.rs
@@ -459,7 +459,12 @@ impl<'a> State<'a> {
             hir::ForeignItemFn(ref decl, ref arg_names, ref generics) => {
                 self.head("")?;
                 self.print_fn(decl,
-                              hir::FnHeader::default(),
+                              hir::FnHeader {
+                                  unsafety: hir::Unsafety::Normal,
+                                  constness: hir::Constness::NotConst,
+                                  abi: Abi::Rust,
+                                  asyncness: hir::IsAsync::NotAsync,
+                              },
                               Some(item.name),
                               generics,
                               &item.vis,
@@ -2253,8 +2258,10 @@ impl<'a> State<'a> {
         };
         self.print_fn(decl,
                       hir::FnHeader {
-                          unsafety, abi,
-                          ..hir::FnHeader::default()
+                          unsafety,
+                          abi,
+                          constness: hir::Constness::NotConst,
+                          asyncness: hir::IsAsync::NotAsync,
                       },
                       name,
                       &generics,
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index 0021ceac315..ad7389db729 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -202,7 +202,7 @@ fn build_external_function(cx: &DocContext, did: DefId) -> clean::Function {
             unsafety: sig.unsafety(),
             abi: sig.abi(),
             constness,
-            ..hir::FnHeader::default()
+            asyncness: hir::IsAsync::NotAsync,
         }
     }
 }
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 7bebefc41f9..057e7f3ab84 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -2457,7 +2457,7 @@ impl<'tcx> Clean<Item> for ty::AssociatedItem {
                             unsafety: sig.unsafety(),
                             abi: sig.abi(),
                             constness,
-                            ..hir::FnHeader::default()
+                            asyncness: hir::IsAsync::NotAsync,
                         }
                     })
                 } else {
@@ -2467,7 +2467,8 @@ impl<'tcx> Clean<Item> for ty::AssociatedItem {
                         header: hir::FnHeader {
                             unsafety: sig.unsafety(),
                             abi: sig.abi(),
-                            ..hir::FnHeader::default()
+                            constness: hir::Constness::NotConst,
+                            asyncness: hir::IsAsync::NotAsync,
                         }
                     })
                 }
@@ -4007,7 +4008,12 @@ impl Clean<Item> for hir::ForeignItem {
                 ForeignFunctionItem(Function {
                     decl,
                     generics,
-                    header: hir::FnHeader::default(),
+                    header: hir::FnHeader {
+                        unsafety: hir::Unsafety::Unsafe,
+                        abi: Abi::Rust,
+                        constness: hir::Constness::NotConst,
+                        asyncness: hir::IsAsync::NotAsync,
+                    },
                 })
             }
             hir::ForeignItemStatic(ref ty, mutbl) => {
diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index a0f29f5918e..f7be4f58dfb 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -2577,20 +2577,20 @@ fn item_function(w: &mut fmt::Formatter, cx: &Context, it: &clean::Item,
     let name_len = format!("{}{}{}{}{:#}fn {}{:#}",
                            VisSpace(&it.visibility),
                            ConstnessSpace(f.header.constness),
-                           AsyncSpace(f.header.asyncness),
                            UnsafetySpace(f.header.unsafety),
+                           AsyncSpace(f.header.asyncness),
                            AbiSpace(f.header.abi),
                            it.name.as_ref().unwrap(),
                            f.generics).len();
     write!(w, "{}<pre class='rust fn'>", render_spotlight_traits(it)?)?;
     render_attributes(w, it)?;
     write!(w,
-           "{vis}{constness}{asyncness}{unsafety}{abi}fn \
+           "{vis}{constness}{unsafety}{asyncness}{abi}fn \
            {name}{generics}{decl}{where_clause}</pre>",
            vis = VisSpace(&it.visibility),
            constness = ConstnessSpace(f.header.constness),
-           asyncness = AsyncSpace(f.header.asyncness),
            unsafety = UnsafetySpace(f.header.unsafety),
+           asyncness = AsyncSpace(f.header.asyncness),
            abi = AbiSpace(f.header.abi),
            name = it.name.as_ref().unwrap(),
            generics = f.generics,
@@ -3024,10 +3024,11 @@ fn render_assoc_item(w: &mut fmt::Formatter,
                 href(did).map(|p| format!("{}#{}.{}", p.0, ty, name)).unwrap_or(anchor)
             }
         };
-        let mut head_len = format!("{}{}{}{:#}fn {}{:#}",
+        let mut head_len = format!("{}{}{}{}{:#}fn {}{:#}",
                                    VisSpace(&meth.visibility),
                                    ConstnessSpace(header.constness),
                                    UnsafetySpace(header.unsafety),
+                                   AsyncSpace(header.asyncness),
                                    AbiSpace(header.abi),
                                    name,
                                    *g).len();
@@ -3038,11 +3039,12 @@ fn render_assoc_item(w: &mut fmt::Formatter,
             (0, true)
         };
         render_attributes(w, meth)?;
-        write!(w, "{}{}{}{}fn <a href='{href}' class='fnname'>{name}</a>\
+        write!(w, "{}{}{}{}{}fn <a href='{href}' class='fnname'>{name}</a>\
                    {generics}{decl}{where_clause}",
                VisSpace(&meth.visibility),
                ConstnessSpace(header.constness),
                UnsafetySpace(header.unsafety),
+               AsyncSpace(header.asyncness),
                AbiSpace(header.abi),
                href = href,
                name = name,