diff --git a/third_party/webrender/patches/004-Fix-more-WebRender-warnings.diff b/third_party/webrender/patches/004-Fix-more-WebRender-warnings.diff
new file mode 100644
index 00000000000..9f6d6316129
--- /dev/null
+++ b/third_party/webrender/patches/004-Fix-more-WebRender-warnings.diff
@@ -0,0 +1,20 @@
+diff --git a/third_party/webrender/webrender_api/src/display_item_cache.rs b/third_party/webrender/webrender_api/src/display_item_cache.rs
+index 169e54797a..8a28ac4ab2 100644
+--- a/third_party/webrender/webrender_api/src/display_item_cache.rs
++++ b/third_party/webrender/webrender_api/src/display_item_cache.rs
+@@ -58,13 +58,13 @@ pub struct DisplayItemCache {
+ 
+ impl DisplayItemCache {
+     fn add_item(&mut self, key: ItemKey, item: CachedDisplayItem) {
+-        let mut entry = &mut self.entries[key as usize];
++        let entry = &mut self.entries[key as usize];
+         entry.items.push(item);
+         entry.occupied = true;
+     }
+ 
+     fn clear_entry(&mut self, key: ItemKey) {
+-        let mut entry = &mut self.entries[key as usize];
++        let entry = &mut self.entries[key as usize];
+         entry.items.clear();
+         entry.occupied = false;
+     }
diff --git a/third_party/webrender/patches/series b/third_party/webrender/patches/series
index ea98b9a1f26..3448f54fb29 100644
--- a/third_party/webrender/patches/series
+++ b/third_party/webrender/patches/series
@@ -1,3 +1,4 @@
 001-Restore-hit-testing-api.diff
 002-Upgrade-version-of-gleam.diff
 003-Fix-WebRender-warnings.diff
+004-Fix-more-WebRender-warnings.diff
diff --git a/third_party/webrender/webrender_api/src/display_item_cache.rs b/third_party/webrender/webrender_api/src/display_item_cache.rs
index 169e54797a9..8a28ac4ab2c 100644
--- a/third_party/webrender/webrender_api/src/display_item_cache.rs
+++ b/third_party/webrender/webrender_api/src/display_item_cache.rs
@@ -58,13 +58,13 @@ pub struct DisplayItemCache {
 
 impl DisplayItemCache {
     fn add_item(&mut self, key: ItemKey, item: CachedDisplayItem) {
-        let mut entry = &mut self.entries[key as usize];
+        let entry = &mut self.entries[key as usize];
         entry.items.push(item);
         entry.occupied = true;
     }
 
     fn clear_entry(&mut self, key: ItemKey) {
-        let mut entry = &mut self.entries[key as usize];
+        let entry = &mut self.entries[key as usize];
         entry.items.clear();
         entry.occupied = false;
     }