diff --git a/crates/codegen/src/class_decl.rs b/crates/codegen/src/class_decl.rs
index e7bd747..902fbe2 100644
--- a/crates/codegen/src/class_decl.rs
+++ b/crates/codegen/src/class_decl.rs
@@ -593,7 +593,7 @@ pub fn gen_method_point(method: &FunctionDecl, ctx: &mut Context, cg: &mut RustC
     cg.addln(" = core::mem::transmute(func_ptr);");
 
     if mutable_self {
-        cg.add_indented("func(self as *mut Self as *const core::ffi::c_void");
+        cg.add_indented("func(self as *mut Self as *mut core::ffi::c_void");
     } else {
         cg.add_indented("func(self as *const Self as *const core::ffi::c_void");
     }
diff --git a/mist-test/src/items/class_test.mist b/mist-test/src/items/class_test.mist
index e6153cf..7562983 100644
--- a/mist-test/src/items/class_test.mist
+++ b/mist-test/src/items/class_test.mist
@@ -22,6 +22,8 @@ pub class Animal
         "Unknown".to_string()
     }
 
+    pub virtual void speak_mut(&mut self){}
+
     pub void test_speak<'a>(&'a self)
     {
         assert_eq!(self.speak(), "Woof!");