diff --git a/core/src/avm2/object/proxy_object.rs b/core/src/avm2/object/proxy_object.rs
index d31e00ee7..eeb49f5ea 100644
--- a/core/src/avm2/object/proxy_object.rs
+++ b/core/src/avm2/object/proxy_object.rs
@@ -3,6 +3,7 @@
 use crate::avm2::activation::Activation;
 use crate::avm2::object::script_object::ScriptObjectData;
 use crate::avm2::object::{ClassObject, Object, ObjectPtr, QNameObject, TObject};
+use crate::avm2::string::AvmString;
 use crate::avm2::value::Value;
 use crate::avm2::Error;
 use crate::avm2::Multiname;
@@ -145,6 +146,21 @@ impl<'gc> TObject<'gc> for ProxyObject<'gc> {
             .coerce_to_boolean())
     }
 
+    fn has_own_property_string(
+        self,
+        name: impl Into<AvmString<'gc>>,
+        activation: &mut Activation<'_, 'gc>,
+    ) -> Result<bool, Error<'gc>> {
+        let name = name.into();
+        Ok(self
+            .call_property(
+                &Multiname::new(activation.avm2().proxy_namespace, "hasProperty"),
+                &[name.into()],
+                activation,
+            )?
+            .coerce_to_boolean())
+    }
+
     fn get_next_enumerant(
         self,
         last_index: u32,