diff --git a/napi-derive-example/src/lib.rs b/napi-derive-example/src/lib.rs
index 6dded1cc..699721a4 100644
--- a/napi-derive-example/src/lib.rs
+++ b/napi-derive-example/src/lib.rs
@@ -8,11 +8,11 @@ use std::convert::TryInto;
 
 register_module!(test_module, init);
 
-fn init(env: &Env, exports: &mut Value<Object>) -> Result<Option<Value<Object>>> {
+fn init(env: &Env, exports: &mut Value<Object>) -> Result<()> {
   exports.set_named_property("testThrow", env.create_function("testThrow", test_throw)?)?;
 
   exports.set_named_property("fibonacci", env.create_function("fibonacci", fibonacci)?)?;
-  Ok(None)
+  Ok(())
 }
 
 #[js_function]
diff --git a/napi-derive/src/lib.rs b/napi-derive/src/lib.rs
index f3b44834..fe647863 100644
--- a/napi-derive/src/lib.rs
+++ b/napi-derive/src/lib.rs
@@ -101,8 +101,8 @@ pub fn js_function(attr: TokenStream, input: TokenStream) -> TokenStream {
         has_error = has_error && (Status::from(status) == Status::Ok);
       }
 
-      let env = Env::from_raw(raw_env);
-      let call_ctx = CallContext::new(env, raw_this, raw_args, #arg_len_span);
+      let mut env = Env::from_raw(raw_env);
+      let call_ctx = CallContext::new(&mut env, raw_this, raw_args, #arg_len_span);
       let result = call_ctx.and_then(|ctx| #new_fn_name(ctx));
       has_error = has_error && result.is_err();
 
diff --git a/napi/Cargo.toml b/napi/Cargo.toml
index eefd3f40..3b0b387c 100644
--- a/napi/Cargo.toml
+++ b/napi/Cargo.toml
@@ -11,13 +11,6 @@ edition = "2018"
 
 [dependencies]
 futures = { version = "0.3", features = ["default", "thread-pool"] }
-serde = { version = "1", optional = true }
-serde_json = { version = "1", optional = true }
-
-[features]
-serde-json = ["serde", "serde_json"]
-
-default = ["serde-json"]
 
 [target.'cfg(windows)'.build-dependencies]
 flate2 = "1.0"
diff --git a/napi/src/call_context.rs b/napi/src/call_context.rs
index d85060ff..4a57daaf 100644
--- a/napi/src/call_context.rs
+++ b/napi/src/call_context.rs
@@ -1,15 +1,16 @@
 use crate::{sys, Any, Env, Error, Result, Status, Value, ValueType};
 
-pub struct CallContext<T: ValueType = Any> {
-  pub env: Env,
+pub struct CallContext<'env, T: ValueType = Any> {
+  pub env: &'env Env,
   pub this: Value<T>,
   args: [sys::napi_value; 8],
   arg_len: usize,
 }
 
-impl<T: ValueType> CallContext<T> {
+impl<'env, T: ValueType> CallContext<'env, T> {
+  #[inline]
   pub fn new(
-    env: Env,
+    env: &'env Env,
     this: sys::napi_value,
     args: [sys::napi_value; 8],
     arg_len: usize,
@@ -22,6 +23,7 @@ impl<T: ValueType> CallContext<T> {
     })
   }
 
+  #[inline]
   pub fn get<ArgType: ValueType>(&self, index: usize) -> Result<Value<ArgType>> {
     if index + 1 > self.arg_len {
       Err(Error {
diff --git a/napi/src/lib.rs b/napi/src/lib.rs
index 8986372d..a7dbb547 100644
--- a/napi/src/lib.rs
+++ b/napi/src/lib.rs
@@ -144,10 +144,15 @@ macro_rules! register_module {
           let result = $init(&env, &mut exports);
 
           match result {
-            Ok(Some(exports)) => exports.into_raw(),
-            Ok(None) => ptr::null_mut(),
+            Ok(_) => exports.into_raw(),
             Err(e) => {
-              let _ = writeln!(::std::io::stderr(), "Error initializing module: {:?}", e);
+              unsafe {
+                sys::napi_throw_error(
+                  raw_env,
+                  ptr::null(),
+                  format!("Error initializing module: {:?}", e).as_ptr() as *const _,
+                )
+              };
               ptr::null_mut()
             }
           }
@@ -221,8 +226,7 @@ impl Env {
 
   pub fn create_uint32(&self, number: u32) -> Result<Value<Number>> {
     let mut raw_value = ptr::null_mut();
-    let status =
-      unsafe { sys::napi_create_uint32(self.0, number, (&mut raw_value) as *mut sys::napi_value) };
+    let status = unsafe { sys::napi_create_uint32(self.0, number, &mut raw_value) };
     check_status(status)?;
     Ok(Value::from_raw_value(self, raw_value, Number::U32(number)))
   }
diff --git a/test_module/src/lib.rs b/test_module/src/lib.rs
index d93cbabd..7131f50e 100644
--- a/test_module/src/lib.rs
+++ b/test_module/src/lib.rs
@@ -9,10 +9,10 @@ use napi::{Any, CallContext, Env, Error, Object, Result, Status, Value};
 
 register_module!(test_module, init);
 
-fn init(env: &Env, exports: &mut Value<Object>) -> Result<Option<Value<Object>>> {
+fn init(env: &Env, exports: &mut Value<Object>) -> Result<()> {
   exports.set_named_property("testSpawn", env.create_function("testSpawn", test_spawn)?)?;
   exports.set_named_property("testThrow", env.create_function("testThrow", test_throw)?)?;
-  Ok(None)
+  Ok(())
 }
 
 #[js_function]