diff --git a/src/host/webaudio/mod.rs b/src/host/webaudio/mod.rs
index dc9c0d9bf..fb835b735 100644
--- a/src/host/webaudio/mod.rs
+++ b/src/host/webaudio/mod.rs
@@ -2,7 +2,6 @@ extern crate js_sys;
 extern crate wasm_bindgen;
 extern crate web_sys;
 
-use self::js_sys::eval;
 use self::wasm_bindgen::prelude::*;
 use self::wasm_bindgen::JsCast;
 use self::web_sys::{AudioContext, AudioContextOptions};
@@ -493,11 +492,9 @@ fn default_output_device() -> Option<Device> {
 
 // Detects whether the `AudioContext` global variable is available.
 fn is_webaudio_available() -> bool {
-    if let Ok(audio_context_is_defined) = eval("typeof AudioContext !== 'undefined'") {
-        audio_context_is_defined.as_bool().unwrap()
-    } else {
-        false
-    }
+    js_sys::Reflect::get(&js_sys::global(), &JsValue::from("AudioContext"))
+        .unwrap()
+        .is_truthy()
 }
 
 // Whether or not the given stream configuration is valid for building a stream.
diff --git a/src/lib.rs b/src/lib.rs
index 98444c239..efea3a379 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -33,7 +33,7 @@
 //! ```
 //!
 //! Before we can create a stream, we must decide what the configuration of the audio stream is
-//! going to be.    
+//! going to be.
 //! You can query all the supported configurations with the
 //! [`supported_input_configs()`] and [`supported_output_configs()`] methods.
 //! These produce a list of [`SupportedStreamConfigRange`] structs which can later be turned into
@@ -225,7 +225,7 @@ pub type FrameCount = u32;
 /// behavior of the given host. Note, the default buffer size may be surprisingly
 /// large, leading to latency issues. If low latency is desired, [`Fixed(FrameCount)`]
 /// should be used in accordance with the [`SupportedBufferSize`] range produced by
-/// the [`SupportedStreamConfig`] API.  
+/// the [`SupportedStreamConfig`] API.
 ///
 /// [`Default`]: BufferSize::Default
 /// [`Fixed(FrameCount)`]: BufferSize::Fixed
@@ -243,7 +243,8 @@ impl wasm_bindgen::describe::WasmDescribe for BufferSize {
 
 #[cfg(target_os = "emscripten")]
 impl wasm_bindgen::convert::IntoWasmAbi for BufferSize {
-    type Abi = Option<u32>;
+    type Abi = <Option<FrameCount> as wasm_bindgen::convert::IntoWasmAbi>::Abi;
+
     fn into_abi(self) -> Self::Abi {
         match self {
             Self::Default => None,