diff --git a/crates/webidl/src/first_pass.rs b/crates/webidl/src/first_pass.rs
index a0614768..c5cb9edd 100644
--- a/crates/webidl/src/first_pass.rs
+++ b/crates/webidl/src/first_pass.rs
@@ -687,4 +687,28 @@ impl<'a> FirstPassRecord<'a> {
             self.fill_superclasses(superclass, set);
         }
     }
+
+    pub fn all_mixins<'me>(&'me self, interface: &str)
+        -> impl Iterator<Item = &'me MixinData<'a>> + 'me
+    {
+        let mut set = Vec::new();
+        self.fill_mixins(interface, interface, &mut set);
+        set.into_iter()
+    }
+
+    fn fill_mixins<'me>(
+        &'me self,
+        self_name: &str,
+        mixin_name: &str,
+        list: &mut Vec<&'me MixinData<'a>>,
+    ) {
+        if let Some(mixin_data) = self.mixins.get(mixin_name) {
+            list.push(mixin_data);
+        }
+        if let Some(mixin_names) = self.includes.get(mixin_name) {
+            for mixin_name in mixin_names {
+                self.fill_mixins(self_name, mixin_name, list);
+            }
+        }
+    }
 }
diff --git a/crates/webidl/src/lib.rs b/crates/webidl/src/lib.rs
index d1b4205e..d6cccbfd 100644
--- a/crates/webidl/src/lib.rs
+++ b/crates/webidl/src/lib.rs
@@ -418,20 +418,11 @@ impl<'src> FirstPassRecord<'src> {
             );
         }
 
-        self.append_interface_mixins(program, name, name);
-    }
-
-    fn append_interface_mixins(
-        &self,
-        program: &mut backend::ast::Program,
-        self_name: &str,
-        mixin_name: &str,
-    ) {
-        if let Some(mixin_data) = self.mixins.get(mixin_name) {
-            for member in &mixin_data.methods {
+        for data in self.all_mixins(name) {
+            for member in &data.methods {
                 self.member_operation(
                     program,
-                    self_name,
+                    name,
                     &member.attributes,
                     None,
                     &[],
@@ -440,13 +431,13 @@ impl<'src> FirstPassRecord<'src> {
                     &member.identifier,
                 );
             }
-            for member in &mixin_data.consts {
-                self.append_const(program, self_name, member);
+            for member in &data.consts {
+                self.append_const(program, name, member);
             }
-            for member in &mixin_data.attributes {
+            for member in &data.attributes {
                 self.member_attribute(
                     program,
-                    self_name,
+                    name,
                     &member.attributes,
                     if let Some(s) = member.stringifier {
                         Some(weedle::interface::StringifierOrInheritOrStatic::Stringifier(s))
@@ -459,11 +450,6 @@ impl<'src> FirstPassRecord<'src> {
                 );
             }
         }
-        if let Some(mixin_names) = self.includes.get(mixin_name) {
-            for mixin_name in mixin_names {
-                self.append_interface_mixins(program, self_name, mixin_name);
-            }
-        }
     }
 
     fn append_constructor(