diff --git a/.changes/fix-custom-protocol-async-linux.md b/.changes/fix-custom-protocol-async-linux.md
new file mode 100644
index 000000000..2ebd8cf0f
--- /dev/null
+++ b/.changes/fix-custom-protocol-async-linux.md
@@ -0,0 +1,5 @@
+---
+"wry": patch
+---
+
+Fixes `with_asynchronous_custom_protocol` crashing when sending the response on Linux.
diff --git a/examples/async_custom_protocol.rs b/examples/async_custom_protocol.rs
index 3d4026faa..757c5bbd9 100644
--- a/examples/async_custom_protocol.rs
+++ b/examples/async_custom_protocol.rs
@@ -9,9 +9,8 @@ use tao::{
   event_loop::{ControlFlow, EventLoop},
   window::WindowBuilder,
 };
-use wry::http::Request;
 use wry::{
-  http::{header::CONTENT_TYPE, Response},
+  http::{header::CONTENT_TYPE, Request, Response},
   WebViewBuilder,
 };
 
diff --git a/examples/custom_protocol.rs b/examples/custom_protocol.rs
index 55e315ba1..b24adc8a4 100644
--- a/examples/custom_protocol.rs
+++ b/examples/custom_protocol.rs
@@ -9,9 +9,8 @@ use tao::{
   event_loop::{ControlFlow, EventLoop},
   window::WindowBuilder,
 };
-use wry::http::Request;
 use wry::{
-  http::{header::CONTENT_TYPE, Response},
+  http::{header::CONTENT_TYPE, Request, Response},
   WebViewBuilder,
 };
 
diff --git a/examples/custom_titlebar.rs b/examples/custom_titlebar.rs
index 74fe9992e..b6c5ca9bc 100644
--- a/examples/custom_titlebar.rs
+++ b/examples/custom_titlebar.rs
@@ -8,8 +8,7 @@ use tao::{
   event_loop::{ControlFlow, EventLoopBuilder},
   window::{CursorIcon, ResizeDirection, Window, WindowBuilder},
 };
-use wry::http::Request;
-use wry::WebViewBuilder;
+use wry::{http::Request, WebViewBuilder};
 
 #[derive(Debug)]
 enum HitTestResult {
diff --git a/examples/gtk_multiwebview.rs b/examples/gtk_multiwebview.rs
index 93078c871..6e6533996 100644
--- a/examples/gtk_multiwebview.rs
+++ b/examples/gtk_multiwebview.rs
@@ -7,8 +7,10 @@ use tao::{
   event_loop::{ControlFlow, EventLoop},
   window::WindowBuilder,
 };
-use wry::dpi::{LogicalPosition, LogicalSize};
-use wry::{Rect, WebViewBuilder};
+use wry::{
+  dpi::{LogicalPosition, LogicalSize},
+  Rect, WebViewBuilder,
+};
 
 fn main() -> wry::Result<()> {
   let event_loop = EventLoop::new();
diff --git a/examples/multiwebview.rs b/examples/multiwebview.rs
index 569ef7594..8380b1320 100644
--- a/examples/multiwebview.rs
+++ b/examples/multiwebview.rs
@@ -7,8 +7,10 @@ use winit::{
   event_loop::{ControlFlow, EventLoop},
   window::WindowBuilder,
 };
-use wry::dpi::{LogicalPosition, LogicalSize};
-use wry::{Rect, WebViewBuilder};
+use wry::{
+  dpi::{LogicalPosition, LogicalSize},
+  Rect, WebViewBuilder,
+};
 
 fn main() -> wry::Result<()> {
   #[cfg(any(
diff --git a/examples/multiwindow.rs b/examples/multiwindow.rs
index d178b4bb1..1a95c09a1 100644
--- a/examples/multiwindow.rs
+++ b/examples/multiwindow.rs
@@ -8,8 +8,7 @@ use tao::{
   event_loop::{ControlFlow, EventLoopBuilder, EventLoopProxy, EventLoopWindowTarget},
   window::{Window, WindowBuilder, WindowId},
 };
-use wry::http::Request;
-use wry::{WebView, WebViewBuilder};
+use wry::{http::Request, WebView, WebViewBuilder};
 
 enum UserEvent {
   CloseWindow(WindowId),
diff --git a/examples/streaming.rs b/examples/streaming.rs
index 858fbc38e..86a9a0dc2 100644
--- a/examples/streaming.rs
+++ b/examples/streaming.rs
@@ -14,9 +14,8 @@ use tao::{
   event_loop::{ControlFlow, EventLoop},
   window::WindowBuilder,
 };
-use wry::http::Request;
 use wry::{
-  http::{header::*, Response},
+  http::{header::*, Request, Response},
   WebViewBuilder,
 };
 
diff --git a/examples/wgpu.rs b/examples/wgpu.rs
index 9b816f73a..c452e48f5 100644
--- a/examples/wgpu.rs
+++ b/examples/wgpu.rs
@@ -4,8 +4,10 @@ use winit::{
   event_loop::{ControlFlow, EventLoop},
   window::Window,
 };
-use wry::dpi::{LogicalPosition, LogicalSize};
-use wry::{Rect, WebViewBuilder};
+use wry::{
+  dpi::{LogicalPosition, LogicalSize},
+  Rect, WebViewBuilder,
+};
 
 async fn run(event_loop: EventLoop<()>, window: Window) {
   let size = window.inner_size();
diff --git a/src/webkitgtk/web_context.rs b/src/webkitgtk/web_context.rs
index db9209d26..df12dec89 100644
--- a/src/webkitgtk/web_context.rs
+++ b/src/webkitgtk/web_context.rs
@@ -5,7 +5,7 @@
 //! Unix platform extensions for [`WebContext`](super::WebContext).
 
 use crate::{web_context::WebContextData, Error, RequestAsyncResponder};
-use gtk::glib;
+use gtk::glib::{self, MainContext};
 use http::{header::CONTENT_TYPE, HeaderName, HeaderValue, Request, Response as HttpResponse};
 use soup::{MessageHeaders, MessageHeadersType};
 use std::{
@@ -21,9 +21,9 @@ use std::{
 };
 use webkit2gtk::{
   ApplicationInfo, AutomationSessionExt, CookiePersistentStorage, DownloadExt, LoadEvent,
-  SecurityManagerExt, URIRequest, URIRequestExt, URISchemeRequestExt, URISchemeResponse,
-  URISchemeResponseExt, UserContentManager, WebContext, WebContextExt as Webkit2gtkContextExt,
-  WebView, WebViewExt,
+  SecurityManagerExt, URIRequest, URIRequestExt, URISchemeRequest, URISchemeRequestExt,
+  URISchemeResponse, URISchemeResponseExt, UserContentManager, WebContext,
+  WebContextExt as Webkit2gtkContextExt, WebView, WebViewExt,
 };
 
 #[derive(Debug)]
@@ -361,28 +361,31 @@ where
         }
       };
 
-      let request_ = request.clone();
+      let request_ = MainThreadRequest(request.clone());
       let responder: Box<dyn FnOnce(HttpResponse<Cow<'static, [u8]>>)> =
         Box::new(move |http_response| {
-          let buffer = http_response.body();
-          let input = gtk::gio::MemoryInputStream::from_bytes(&gtk::glib::Bytes::from(buffer));
-          let content_type = http_response
-            .headers()
-            .get(CONTENT_TYPE)
-            .and_then(|h| h.to_str().ok());
-
-          let response = URISchemeResponse::new(&input, buffer.len() as i64);
-          response.set_status(http_response.status().as_u16() as u32, None);
-          if let Some(content_type) = content_type {
-            response.set_content_type(content_type);
-          }
+          MainContext::default().invoke(move || {
+            let buffer = http_response.body();
+            let input = gtk::gio::MemoryInputStream::from_bytes(&gtk::glib::Bytes::from(buffer));
+            let content_type = http_response
+              .headers()
+              .get(CONTENT_TYPE)
+              .and_then(|h| h.to_str().ok());
+
+            let response = URISchemeResponse::new(&input, buffer.len() as i64);
+            response.set_status(http_response.status().as_u16() as u32, None);
+            if let Some(content_type) = content_type {
+              response.set_content_type(content_type);
+            }
+
+            let headers = MessageHeaders::new(MessageHeadersType::Response);
+            for (name, value) in http_response.headers().into_iter() {
+              headers.append(name.as_str(), value.to_str().unwrap_or(""));
+            }
+            response.set_http_headers(headers);
+            request_.finish_with_response(&response);
+          });
 
-          let headers = MessageHeaders::new(MessageHeadersType::Response);
-          for (name, value) in http_response.headers().into_iter() {
-            headers.append(name.as_str(), value.to_str().unwrap_or(""));
-          }
-          response.set_http_headers(headers);
-          request_.finish_with_response(&response);
         });
 
       #[cfg(feature = "tracing")]
@@ -399,6 +402,17 @@ where
   Ok(())
 }
 
+struct MainThreadRequest(URISchemeRequest);
+
+impl MainThreadRequest {
+  fn finish_with_response(&self, response: &URISchemeResponse) {
+    self.0.finish_with_response(response);
+  }
+}
+
+unsafe impl Send for MainThreadRequest {}
+unsafe impl Sync for MainThreadRequest {}
+
 #[derive(Debug)]
 struct WebviewUriRequest {
   webview: WebView,
diff --git a/src/wkwebview/mod.rs b/src/wkwebview/mod.rs
index f4dd5f402..ad629dd7a 100644
--- a/src/wkwebview/mod.rs
+++ b/src/wkwebview/mod.rs
@@ -32,8 +32,10 @@ use std::{
   sync::{Arc, Mutex},
 };
 
-use core_graphics::base::CGFloat;
-use core_graphics::geometry::{CGPoint, CGRect, CGSize};
+use core_graphics::{
+  base::CGFloat,
+  geometry::{CGPoint, CGRect, CGSize},
+};
 
 use objc::{
   declare::ClassDecl,