diff --git a/lib/interface-types/README.md b/lib/interface-types/README.md
new file mode 100644
index 000000000..8dcf3ffc8
--- /dev/null
+++ b/lib/interface-types/README.md
@@ -0,0 +1,32 @@
+<p align="center">
+  <a href="https://wasmer.io" target="_blank" rel="noopener noreferrer">
+    <img width="300" src="https://raw.githubusercontent.com/wasmerio/wasmer/master/logo.png" alt="Wasmer logo">
+  </a>
+</p>
+
+<p align="center">
+  <a href="https://dev.azure.com/wasmerio/wasmer/_build/latest?definitionId=3&branchName=master">
+    <img src="https://img.shields.io/azure-devops/build/wasmerio/wasmer/3.svg?style=flat-square" alt="Build Status">
+  </a>
+  <a href="https://github.com/wasmerio/wasmer/blob/master/LICENSE">
+    <img src="https://img.shields.io/github/license/wasmerio/wasmer.svg?style=flat-square" alt="License">
+  </a>
+  <a href="https://spectrum.chat/wasmer">
+    <img src="https://withspectrum.github.io/badge/badge.svg" alt="Join the Wasmer Community">
+  </a>
+  <a href="https://crates.io/crates/wasmer-interface-types">
+    <img src="https://img.shields.io/crates/d/wasmer-interface-types.svg?style=flat-square" alt="Number of downloads from crates.io">
+  </a>
+  <a href="https://docs.rs/wasmer-interface-types">
+    <img src="https://docs.rs/wasmer-interface-types/badge.svg" alt="Read our API documentation">
+  </a>
+</p>
+
+# Wasmer Interface Types
+
+Wasmer is a standalone JIT WebAssembly runtime, aiming to be fully
+compatible with WASI, Emscripten, Rust and Go. [Learn
+more](https://github.com/wasmerio/wasmer).
+
+This crate is an implementation of [the living WebAssembly Interface
+Types standard](https://github.com/WebAssembly/interface-types).
diff --git a/lib/runtime-core/src/typed_func.rs b/lib/runtime-core/src/typed_func.rs
index 405853a5d..ad4b5078e 100644
--- a/lib/runtime-core/src/typed_func.rs
+++ b/lib/runtime-core/src/typed_func.rs
@@ -314,6 +314,7 @@ macro_rules! impl_traits {
         where
             $( $x: WasmExternType ),*;
 
+        #[allow(unused_parens)]
         impl< $( $x ),* > WasmTypeList for ( $( $x ),* )
         where
             $( $x: WasmExternType ),*
@@ -384,6 +385,7 @@ macro_rules! impl_traits {
             }
         }
 
+        #[allow(unused_parens)]
         impl< $( $x, )* Rets, Trap, FN > HostFunction<ExplicitVmCtx, ( $( $x ),* ), Rets> for FN
         where
             $( $x: WasmExternType, )*
@@ -499,6 +501,7 @@ macro_rules! impl_traits {
             }
         }
 
+        #[allow(unused_parens)]
         impl< $( $x, )* Rets, Trap, FN > HostFunction<ImplicitVmCtx, ( $( $x ),* ), Rets> for FN
         where
             $( $x: WasmExternType, )*
@@ -611,6 +614,7 @@ macro_rules! impl_traits {
             }
         }
 
+        #[allow(unused_parens)]
         impl<'a $( , $x )*, Rets> Func<'a, ( $( $x ),* ), Rets, Wasm>
         where
             $( $x: WasmExternType, )*
diff --git a/lib/runtime-core/src/types.rs b/lib/runtime-core/src/types.rs
index 1b19bbc3d..615964bb0 100644
--- a/lib/runtime-core/src/types.rs
+++ b/lib/runtime-core/src/types.rs
@@ -104,44 +104,57 @@ where
 {
     /// Type for this `NativeWasmType`.
     const TYPE: Type;
+
     /// Convert from u64 bites to self.
     fn from_binary(bits: u64) -> Self;
+
     /// Convert self to u64 binary representation.
     fn to_binary(self) -> u64;
 }
 
 unsafe impl NativeWasmType for i32 {
     const TYPE: Type = Type::I32;
+
     fn from_binary(bits: u64) -> Self {
         bits as _
     }
+
     fn to_binary(self) -> u64 {
         self as _
     }
 }
+
 unsafe impl NativeWasmType for i64 {
     const TYPE: Type = Type::I64;
+
     fn from_binary(bits: u64) -> Self {
         bits as _
     }
+
     fn to_binary(self) -> u64 {
         self as _
     }
 }
+
 unsafe impl NativeWasmType for f32 {
     const TYPE: Type = Type::F32;
+
     fn from_binary(bits: u64) -> Self {
         f32::from_bits(bits as u32)
     }
+
     fn to_binary(self) -> u64 {
         self.to_bits() as _
     }
 }
+
 unsafe impl NativeWasmType for f64 {
     const TYPE: Type = Type::F64;
+
     fn from_binary(bits: u64) -> Self {
         f64::from_bits(bits)
     }
+
     fn to_binary(self) -> u64 {
         self.to_bits()
     }
@@ -154,103 +167,41 @@ where
 {
     /// Native wasm type for this `WasmExternType`.
     type Native: NativeWasmType;
+
     /// Convert from given `Native` type to self.
     fn from_native(native: Self::Native) -> Self;
+
     /// Convert self to `Native` type.
     fn to_native(self) -> Self::Native;
 }
 
-unsafe impl WasmExternType for i8 {
-    type Native = i32;
-    fn from_native(native: Self::Native) -> Self {
-        native as _
-    }
-    fn to_native(self) -> Self::Native {
-        self as _
-    }
-}
-unsafe impl WasmExternType for u8 {
-    type Native = i32;
-    fn from_native(native: Self::Native) -> Self {
-        native as _
-    }
-    fn to_native(self) -> Self::Native {
-        self as _
-    }
-}
-unsafe impl WasmExternType for i16 {
-    type Native = i32;
-    fn from_native(native: Self::Native) -> Self {
-        native as _
-    }
-    fn to_native(self) -> Self::Native {
-        self as _
-    }
-}
-unsafe impl WasmExternType for u16 {
-    type Native = i32;
-    fn from_native(native: Self::Native) -> Self {
-        native as _
-    }
-    fn to_native(self) -> Self::Native {
-        self as _
-    }
-}
-unsafe impl WasmExternType for i32 {
-    type Native = i32;
-    fn from_native(native: Self::Native) -> Self {
-        native
-    }
-    fn to_native(self) -> Self::Native {
-        self
-    }
-}
-unsafe impl WasmExternType for u32 {
-    type Native = i32;
-    fn from_native(native: Self::Native) -> Self {
-        native as _
-    }
-    fn to_native(self) -> Self::Native {
-        self as _
-    }
-}
-unsafe impl WasmExternType for i64 {
-    type Native = i64;
-    fn from_native(native: Self::Native) -> Self {
-        native
-    }
-    fn to_native(self) -> Self::Native {
-        self
-    }
-}
-unsafe impl WasmExternType for u64 {
-    type Native = i64;
-    fn from_native(native: Self::Native) -> Self {
-        native as _
-    }
-    fn to_native(self) -> Self::Native {
-        self as _
-    }
-}
-unsafe impl WasmExternType for f32 {
-    type Native = f32;
-    fn from_native(native: Self::Native) -> Self {
-        native
-    }
-    fn to_native(self) -> Self::Native {
-        self
-    }
-}
-unsafe impl WasmExternType for f64 {
-    type Native = f64;
-    fn from_native(native: Self::Native) -> Self {
-        native
-    }
-    fn to_native(self) -> Self::Native {
-        self
-    }
+macro_rules! wasm_extern_type {
+    ($type:ty => $native_type:ty) => {
+        unsafe impl WasmExternType for $type {
+            type Native = $native_type;
+
+            fn from_native(native: Self::Native) -> Self {
+                native as _
+            }
+
+            fn to_native(self) -> Self::Native {
+                self as _
+            }
+        }
+    };
 }
 
+wasm_extern_type!(i8 => i32);
+wasm_extern_type!(u8 => i32);
+wasm_extern_type!(i16 => i32);
+wasm_extern_type!(u16 => i32);
+wasm_extern_type!(i32 => i32);
+wasm_extern_type!(u32 => i32);
+wasm_extern_type!(i64 => i64);
+wasm_extern_type!(u64 => i64);
+wasm_extern_type!(f32 => f32);
+wasm_extern_type!(f64 => f64);
+
 // pub trait IntegerAtomic
 // where
 //     Self: Sized