diff --git a/components/layout/context.rs b/components/layout/context.rs
index 0b3973eac05..308295f4196 100644
--- a/components/layout/context.rs
+++ b/components/layout/context.rs
@@ -77,7 +77,7 @@ pub struct SharedLayoutContext {
     pub style_context: SharedStyleContext,
 
     /// The shared image cache thread.
-    pub image_cache_thread: ImageCacheThread,
+    pub image_cache_thread: Mutex<ImageCacheThread>,
 
     /// A channel for the image cache to send responses to.
     pub image_cache_sender: Mutex<ImageCacheChan>,
@@ -133,7 +133,8 @@ impl SharedLayoutContext {
         debug_assert!(opts::get().output_file.is_some() || opts::get().exit_after_load);
 
         // See if the image is already available
-        let result = self.image_cache_thread.find_image(url.clone(), use_placeholder);
+        let result = self.image_cache_thread.lock().unwrap()
+                                            .find_image(url.clone(), use_placeholder);
 
         match result {
             Ok(image) => return Some(image),
@@ -147,7 +148,7 @@ impl SharedLayoutContext {
         // If we are emitting an output file, then we need to block on
         // image load or we risk emitting an output file missing the image.
         let (sync_tx, sync_rx) = ipc::channel().unwrap();
-        self.image_cache_thread.request_image(url, ImageCacheChan(sync_tx), None);
+        self.image_cache_thread.lock().unwrap().request_image(url, ImageCacheChan(sync_tx), None);
         loop {
             match sync_rx.recv() {
                 Err(_) => return None,
@@ -171,7 +172,8 @@ impl SharedLayoutContext {
                        .map(|img| ImageOrMetadataAvailable::ImageAvailable(img));
         }
         // See if the image is already available
-        let result = self.image_cache_thread.find_image_or_metadata(url.clone(),
+        let result = self.image_cache_thread.lock().unwrap()
+                                            .find_image_or_metadata(url.clone(),
                                                                     use_placeholder);
         match result {
             Ok(image_or_metadata) => Some(image_or_metadata),
@@ -180,7 +182,8 @@ impl SharedLayoutContext {
             // Not yet requested, async mode - request image or metadata from the cache
             Err(ImageState::NotRequested) => {
                 let sender = self.image_cache_sender.lock().unwrap().clone();
-                self.image_cache_thread.request_image_and_metadata(url, sender, None);
+                self.image_cache_thread.lock().unwrap()
+                                       .request_image_and_metadata(url, sender, None);
                 None
             }
             // Image has been requested, is still pending. Return no image for this paint loop.
diff --git a/components/layout_thread/lib.rs b/components/layout_thread/lib.rs
index 788fff29a5c..8d7335db40c 100644
--- a/components/layout_thread/lib.rs
+++ b/components/layout_thread/lib.rs
@@ -511,7 +511,7 @@ impl LayoutThread {
                 local_context_creation_data: Mutex::new(local_style_context_creation_data),
                 timer: self.timer.clone(),
             },
-            image_cache_thread: self.image_cache_thread.clone(),
+            image_cache_thread: Mutex::new(self.image_cache_thread.clone()),
             image_cache_sender: Mutex::new(self.image_cache_sender.clone()),
             font_cache_thread: Mutex::new(self.font_cache_thread.clone()),
             webrender_image_cache: self.webrender_image_cache.clone(),