diff --git a/crates/wasm-bindgen-cli-support/src/lib.rs b/crates/wasm-bindgen-cli-support/src/lib.rs
index 4b835014..28677ecb 100644
--- a/crates/wasm-bindgen-cli-support/src/lib.rs
+++ b/crates/wasm-bindgen-cli-support/src/lib.rs
@@ -109,6 +109,7 @@ fn extract_program(module: &mut Module) -> shared::Program {
         structs: Vec::new(),
         free_functions: Vec::new(),
         imports: Vec::new(),
+        imported_structs: Vec::new(),
     };
     let data = match data {
         Some(data) => data,
@@ -126,10 +127,11 @@ fn extract_program(module: &mut Module) -> shared::Program {
                 Ok(f) => f,
                 Err(_) => continue,
             };
-            let shared::Program { structs, free_functions, imports } = p;
+            let shared::Program { structs, free_functions, imports, imported_structs } = p;
             ret.structs.extend(structs);
             ret.free_functions.extend(free_functions);
             ret.imports.extend(imports);
+            ret.imported_structs.extend(imported_structs);
         }
         data.entries_mut().remove(i);
     }
diff --git a/crates/wasm-bindgen-macro/src/ast.rs b/crates/wasm-bindgen-macro/src/ast.rs
index 8ad348e3..dddb8570 100644
--- a/crates/wasm-bindgen-macro/src/ast.rs
+++ b/crates/wasm-bindgen-macro/src/ast.rs
@@ -6,6 +6,7 @@ pub struct Program {
     pub structs: Vec<Struct>,
     pub free_functions: Vec<Function>,
     pub imports: Vec<Import>,
+    pub imported_structs: Vec<ImportStruct>,
 }
 
 pub struct Function {
@@ -16,11 +17,21 @@ pub struct Function {
 
 pub struct Import {
     pub module: String,
-    pub function: Function,
-    pub decl: Box<syn::FnDecl>,
+    pub function: ImportFunction,
+}
+
+pub struct ImportFunction {
     pub ident: syn::Ident,
-    pub vis: syn::Visibility,
-    pub attrs: Vec<syn::Attribute>,
+    pub wasm_function: Function,
+    pub rust_decl: Box<syn::FnDecl>,
+    pub rust_vis: syn::Visibility,
+    pub rust_attrs: Vec<syn::Attribute>,
+}
+
+pub struct ImportStruct {
+    pub module: Option<String>,
+    pub name: syn::Ident,
+    pub functions: Vec<(bool, ImportFunction)>,
 }
 
 pub enum Type {
@@ -103,23 +114,51 @@ impl Program {
             })
             .expect("must specify `#[wasm_module = ...]` for module to import from");
         for item in f.items.iter() {
-            self.push_foreign_item(&module, item);
+            let import = self.gen_foreign_item(item, false).0;
+            self.imports.push(Import {
+                module: module.clone(),
+                function: import,
+            });
         }
     }
 
-    pub fn push_foreign_item(&mut self, module: &str, f: &syn::ForeignItem) {
+    pub fn gen_foreign_item(&mut self,
+                            f: &syn::ForeignItem,
+                            allow_self: bool) -> (ImportFunction, bool) {
         let f = match *f {
             syn::ForeignItem::Fn(ref f) => f,
             _ => panic!("only foreign functions allowed for now, not statics"),
         };
 
-        self.imports.push(Import {
-            module: module.to_string(),
-            attrs: f.attrs.clone(),
-            vis: f.vis.clone(),
-            decl: f.decl.clone(),
+        let (wasm, mutable) = Function::from_decl(f.ident, &f.decl, allow_self);
+        let is_method = match mutable {
+            Some(false) => true,
+            None => false,
+            Some(true) => {
+                panic!("mutable self methods not allowed in extern structs");
+            }
+        };
+
+        (ImportFunction {
+            rust_attrs: f.attrs.clone(),
+            rust_vis: f.vis.clone(),
+            rust_decl: f.decl.clone(),
             ident: f.ident.clone(),
-            function: Function::from_decl(f.ident, &f.decl),
+            wasm_function: wasm,
+        }, is_method)
+    }
+
+    pub fn push_extern_class(&mut self, class: &ExternClass) {
+        let functions = class.functions.iter()
+            .map(|f| {
+                let (f, method) = self.gen_foreign_item(f, true);
+                (method, f)
+            })
+            .collect();
+        self.imported_structs.push(ImportStruct {
+            module: class.module.as_ref().map(|s| s.value()),
+            name: class.name,
+            functions,
         });
     }
 
@@ -128,7 +167,10 @@ impl Program {
             structs: self.structs.iter().map(|s| s.shared()).collect(),
             free_functions: self.free_functions.iter().map(|s| s.shared()).collect(),
             imports: self.imports.iter()
-                .map(|i| (i.module.clone(), i.function.shared()))
+                .map(|i| (i.module.clone(), i.function.wasm_function.shared()))
+                .collect(),
+            imported_structs: self.imported_structs.iter()
+                .map(|i| i.shared())
                 .collect(),
         }
     }
@@ -153,10 +195,12 @@ impl Function {
             panic!("can only bindgen Rust ABI functions")
         }
 
-        Function::from_decl(input.ident, &input.decl)
+        Function::from_decl(input.ident, &input.decl, false).0
     }
 
-    pub fn from_decl(name: syn::Ident, decl: &syn::FnDecl) -> Function {
+    pub fn from_decl(name: syn::Ident,
+                     decl: &syn::FnDecl,
+                     allow_self: bool) -> (Function, Option<bool>) {
         if decl.variadic.is_some() {
             panic!("can't bindgen variadic functions")
         }
@@ -164,10 +208,19 @@ impl Function {
             panic!("can't bindgen functions with lifetime or type parameters")
         }
 
+        let mut mutable = None;
         let arguments = decl.inputs.iter()
-            .map(|arg| {
+            .filter_map(|arg| {
                 match *arg {
-                    syn::FnArg::Captured(ref c) => c,
+                    syn::FnArg::Captured(ref c) => Some(c),
+                    syn::FnArg::SelfValue(_) => {
+                        panic!("by-value `self` not yet supported");
+                    }
+                    syn::FnArg::SelfRef(ref a) if allow_self => {
+                        assert!(mutable.is_none());
+                        mutable = Some(a.mutability.is_some());
+                        None
+                    }
                     _ => panic!("arguments cannot be `self` or ignored"),
                 }
             })
@@ -179,7 +232,7 @@ impl Function {
             syn::ReturnType::Type(_, ref t) => Some(Type::from(t)),
         };
 
-        Function { name, arguments, ret }
+        (Function { name, arguments, ret }, mutable)
     }
 
     pub fn free_function_export_name(&self) -> syn::LitStr {
@@ -346,38 +399,9 @@ impl Struct {
             panic!("can only bindgen safe functions");
         }
 
-        if method.sig.decl.variadic.is_some() {
-            panic!("can't bindgen variadic functions")
-        }
-        if method.sig.decl.generics.params.len() > 0 {
-            panic!("can't bindgen functions with lifetime or type parameters")
-        }
-
-        let mut mutable = None;
-        let arguments = method.sig.decl.inputs.iter()
-            .filter_map(|arg| {
-                match *arg {
-                    syn::FnArg::Captured(ref c) => Some(c),
-                    syn::FnArg::SelfValue(_) => {
-                        panic!("by-value `self` not yet supported");
-                    }
-                    syn::FnArg::SelfRef(ref a) => {
-                        assert!(mutable.is_none());
-                        mutable = Some(a.mutability.is_some());
-                        None
-                    }
-                    _ => panic!("arguments cannot be `self` or ignored"),
-                }
-            })
-            .map(|arg| Type::from(&arg.ty))
-            .collect::<Vec<_>>();
-
-        let ret = match method.sig.decl.output {
-            syn::ReturnType::Default => None,
-            syn::ReturnType::Type(_, ref t) => Some(Type::from(t)),
-        };
-
-        let function = Function { name: method.sig.ident, arguments, ret };
+        let (function, mutable) = Function::from_decl(method.sig.ident,
+                                                      &method.sig.decl,
+                                                      true);
         match mutable {
             Some(mutable) => {
                 self.methods.push(Method { mutable, function });
@@ -405,3 +429,77 @@ impl Method {
         }
     }
 }
+
+impl ImportStruct {
+    fn shared(&self) -> shared::ImportStruct {
+        shared::ImportStruct {
+            module: self.module.clone(),
+            name: self.name.to_string(),
+            functions: self.functions.iter()
+                .map(|&(b, ref f)| (b, f.wasm_function.shared()))
+                .collect(),
+        }
+    }
+}
+
+pub struct File {
+    pub items: Vec<MyItem>,
+}
+
+impl syn::synom::Synom for File {
+    named!(parse -> Self, map!(many0!(syn!(MyItem)), |items| File { items }));
+}
+
+pub enum MyItem {
+    Normal(syn::Item),
+    ExternClass(ExternClass),
+}
+
+impl syn::synom::Synom for MyItem {
+    named!(parse -> Self, alt!(
+        syn!(syn::Item) => { MyItem::Normal }
+        |
+        syn!(ExternClass) => { MyItem::ExternClass }
+    ));
+}
+
+pub struct ExternClass {
+    name: syn::Ident,
+    module: Option<syn::LitStr>,
+    functions: Vec<syn::ForeignItem>,
+}
+
+impl syn::synom::Synom for ExternClass {
+    named!(parse -> Self, do_parse!(
+        module: option!(do_parse!(
+            punct!(#) >>
+            name: brackets!(do_parse!(
+                call!(term, "wasm_module") >>
+                punct!(=) >>
+                val: syn!(syn::LitStr) >>
+                (val)
+            )) >>
+            (name.1)
+        )) >>
+        keyword!(extern) >>
+        keyword!(struct) >>
+        name: syn!(syn::Ident) >>
+        items: braces!(many0!(syn!(syn::ForeignItem))) >>
+        (ExternClass {
+            name,
+            module,
+            functions: items.1,
+        })
+    ));
+}
+
+fn term<'a>(cursor: syn::buffer::Cursor<'a>, name: &str)
+    -> syn::synom::PResult<'a, ()>
+{
+    if let Some((_span, term, next)) = cursor.term() {
+        if term.as_str() == name {
+            return Ok(((), next))
+        }
+    }
+    syn::parse_error()
+}
diff --git a/crates/wasm-bindgen-macro/src/lib.rs b/crates/wasm-bindgen-macro/src/lib.rs
index 5c58392c..a7a26953 100644
--- a/crates/wasm-bindgen-macro/src/lib.rs
+++ b/crates/wasm-bindgen-macro/src/lib.rs
@@ -1,5 +1,6 @@
 #![feature(proc_macro)]
 
+#[macro_use]
 extern crate syn;
 #[macro_use]
 extern crate quote;
@@ -26,7 +27,7 @@ macro_rules! my_quote {
 #[proc_macro]
 pub fn wasm_bindgen(input: TokenStream) -> TokenStream {
     // Parse the input as a list of Rust items, reusing the `syn::File` parser.
-    let file = syn::parse::<syn::File>(input)
+    let file = syn::parse::<ast::File>(input)
         .expect("expected a set of valid Rust items");
 
     let mut ret = Tokens::new();
@@ -35,12 +36,21 @@ pub fn wasm_bindgen(input: TokenStream) -> TokenStream {
         structs: Vec::new(),
         free_functions: Vec::new(),
         imports: Vec::new(),
+        imported_structs: Vec::new(),
     };
 
     // Translate all input items into our own internal representation (the `ast`
     // module). We'll be panicking here on anything that we can't process
 
     for item in file.items.iter() {
+        let item = match *item {
+            ast::MyItem::ExternClass(ref c) => {
+                program.push_extern_class(c);
+                continue
+            }
+            ast::MyItem::Normal(ref item) => item,
+        };
+
         match *item {
             syn::Item::Fn(ref f) => {
                 item.to_tokens(&mut ret);
@@ -76,6 +86,9 @@ pub fn wasm_bindgen(input: TokenStream) -> TokenStream {
     for i in program.imports.iter() {
         bindgen_import(i, &mut ret);
     }
+    for i in program.imported_structs.iter() {
+        bindgen_imported_struct(i, &mut ret);
+    }
 
     // Finally generate a static which will eventually be what lives in a custom
     // section of the wasm executable. For now it's just a plain old static, but
@@ -416,18 +429,53 @@ impl ToTokens for Receiver {
 }
 
 fn bindgen_import(import: &ast::Import, tokens: &mut Tokens) {
-    let vis = &import.vis;
-    let ret = &import.decl.output;
-    let name = &import.ident;
-    let fn_token = &import.decl.fn_token;
-    let arguments = &import.decl.inputs;
+    bindgen_import_function(&import.function,
+                            &import.function.ident.to_string(),
+                            Some(&import.module),
+                            tokens);
+}
+
+fn bindgen_imported_struct(import: &ast::ImportStruct, tokens: &mut Tokens) {
+    let name = import.name;
+    (my_quote! {
+        pub struct #name {
+            obj: ::wasm_bindgen::JsObject,
+        }
+    }).to_tokens(tokens);
+
+    let mut methods = Tokens::new();
+
+    for &(_is_method, ref f) in import.functions.iter() {
+        let import_name = format!("__wbg_{}_{}", name, f.ident);
+
+        bindgen_import_function(f,
+                                &import_name,
+                                import.module.as_ref().map(|s| &**s),
+                                &mut methods);
+    }
+
+    (my_quote! {
+        impl #name {
+            #methods
+        }
+    }).to_tokens(tokens);
+}
+
+fn bindgen_import_function(import: &ast::ImportFunction,
+                           import_name: &str,
+                           _import_module: Option<&str>,
+                           tokens: &mut Tokens) {
+    let vis = &import.rust_vis;
+    let ret = &import.rust_decl.output;
+    let fn_token = &import.rust_decl.fn_token;
+    let arguments = &import.rust_decl.inputs;
 
     let mut abi_argument_names = Vec::new();
     let mut abi_arguments = Vec::new();
     let mut arg_conversions = Vec::new();
     let ret_ident = syn::Ident::from("_ret");
 
-    let names = import.decl.inputs
+    let names = import.rust_decl.inputs
         .iter()
         .map(|arg| {
             match *arg {
@@ -449,7 +497,7 @@ fn bindgen_import(import: &ast::Import, tokens: &mut Tokens) {
             }
         });
 
-    for (ty, name) in import.function.arguments.iter().zip(names) {
+    for (ty, name) in import.wasm_function.arguments.iter().zip(names) {
         match *ty {
             ast::Type::Integer(i) => {
                 abi_argument_names.push(name);
@@ -507,7 +555,7 @@ fn bindgen_import(import: &ast::Import, tokens: &mut Tokens) {
     }
     let abi_ret;
     let convert_ret;
-    match import.function.ret {
+    match import.wasm_function.ret {
         Some(ast::Type::Integer(i)) => {
             abi_ret = my_quote! { #i };
             convert_ret = my_quote! { #ret_ident };
@@ -542,14 +590,16 @@ fn bindgen_import(import: &ast::Import, tokens: &mut Tokens) {
         }
     }
 
+    let name = import.ident;
+    let import_name = syn::Ident::from(import_name);
     (quote! {
         #vis #fn_token #name(#arguments) #ret {
             extern {
-                fn #name(#(#abi_arguments),*) -> #abi_ret;
+                fn #import_name(#(#abi_arguments),*) -> #abi_ret;
             }
             unsafe {
                 #(#arg_conversions)*
-                let #ret_ident = #name(#(#abi_argument_names),*);
+                let #ret_ident = #import_name(#(#abi_argument_names),*);
                 #convert_ret
             }
         }
diff --git a/crates/wasm-bindgen-shared/src/lib.rs b/crates/wasm-bindgen-shared/src/lib.rs
index f8e13e53..38aa1cd4 100644
--- a/crates/wasm-bindgen-shared/src/lib.rs
+++ b/crates/wasm-bindgen-shared/src/lib.rs
@@ -6,6 +6,7 @@ pub struct Program {
     pub structs: Vec<Struct>,
     pub free_functions: Vec<Function>,
     pub imports: Vec<(String, Function)>,
+    pub imported_structs: Vec<ImportStruct>,
 }
 
 #[derive(Serialize, Deserialize)]
@@ -15,6 +16,13 @@ pub struct Struct {
     pub methods: Vec<Method>,
 }
 
+#[derive(Serialize, Deserialize)]
+pub struct ImportStruct {
+    pub module: Option<String>,
+    pub name: String,
+    pub functions: Vec<(bool, Function)>,
+}
+
 #[derive(Serialize, Deserialize)]
 pub struct Method {
     pub mutable: bool,
diff --git a/tests/import-class.rs b/tests/import-class.rs
new file mode 100644
index 00000000..a23b174b
--- /dev/null
+++ b/tests/import-class.rs
@@ -0,0 +1,31 @@
+extern crate test_support;
+
+#[test]
+fn simple() {
+    test_support::project()
+        .file("src/lib.rs", r#"
+            #![feature(proc_macro)]
+
+            extern crate wasm_bindgen;
+
+            use wasm_bindgen::prelude::*;
+
+            wasm_bindgen! {
+                extern struct Math {
+                    fn random() -> f64;
+                }
+
+                pub fn get_random() -> f64 {
+                    Math::random()
+                }
+            }
+        "#)
+        .file("test.ts", r#"
+            import * as wasm from "./out";
+
+            export function test() {
+                wasm.get_random();
+            }
+        "#)
+        .test();
+}