diff --git a/core/src/avm2/domain.rs b/core/src/avm2/domain.rs
index da88a3510..ceae63fc9 100644
--- a/core/src/avm2/domain.rs
+++ b/core/src/avm2/domain.rs
@@ -219,6 +219,15 @@ impl<'gc> Domain<'gc> {
         res
     }
 
+    pub fn get_defined_names(&self) -> Vec<QName<'gc>> {
+        self.0
+            .read()
+            .defs
+            .iter()
+            .map(|(name, namespace, _)| QName::new(namespace, name))
+            .collect()
+    }
+
     /// Export a definition from a script into the current application domain.
     ///
     /// This does nothing if the definition already exists.
diff --git a/core/src/avm2/globals/flash/system/ApplicationDomain.as b/core/src/avm2/globals/flash/system/ApplicationDomain.as
index 216bfa9cb..21d0f38a2 100644
--- a/core/src/avm2/globals/flash/system/ApplicationDomain.as
+++ b/core/src/avm2/globals/flash/system/ApplicationDomain.as
@@ -17,5 +17,7 @@ package flash.system {
 
         public native function getDefinition(name:String):Object;
         public native function hasDefinition(name:String):Boolean;
+
+        public native function getQualifiedDefinitionNames():Vector.<String>;
     }
 }
diff --git a/core/src/avm2/globals/flash/system/application_domain.rs b/core/src/avm2/globals/flash/system/application_domain.rs
index b39bf2a8c..7ece4a054 100644
--- a/core/src/avm2/globals/flash/system/application_domain.rs
+++ b/core/src/avm2/globals/flash/system/application_domain.rs
@@ -1,9 +1,10 @@
 //! `flash.system.ApplicationDomain` class
 
 use crate::avm2::activation::Activation;
-use crate::avm2::object::{DomainObject, Object, TObject};
+use crate::avm2::object::{DomainObject, Object, TObject, VectorObject};
 use crate::avm2::parameters::ParametersExt;
 use crate::avm2::value::Value;
+use crate::avm2::vector::VectorStorage;
 use crate::avm2::QName;
 use crate::avm2::{Domain, Error};
 
@@ -102,6 +103,40 @@ pub fn has_definition<'gc>(
     Ok(Value::Undefined)
 }
 
+/// 'getQualifiedDefinitionNames' method.
+///
+/// NOTE: Normally only available in Flash Player 11.3+.
+pub fn get_qualified_definition_names<'gc>(
+    activation: &mut Activation<'_, 'gc>,
+    this: Option<Object<'gc>>,
+    _args: &[Value<'gc>],
+) -> Result<Value<'gc>, Error<'gc>> {
+    if let Some(appdomain) = this.and_then(|this| this.as_application_domain()) {
+        // NOTE: According to the docs of 'getQualifiedDeinitionNames',
+        // it is able to throw a 'SecurityError' if "The definition belongs
+        // to a domain to which the calling code does not have access."
+        //
+        // We do not implement this.
+
+        let storage = VectorStorage::from_values(
+            appdomain
+                .get_defined_names()
+                .iter()
+                .filter(|name| !name.namespace().is_private())
+                .map(|name| Value::String(name.to_qualified_name(activation.context.gc_context)))
+                .collect(),
+            false,
+            activation.avm2().classes().string,
+        );
+
+        let name_array = VectorObject::from_vector(storage, activation)?;
+
+        return Ok(name_array.into());
+    }
+
+    Ok(Value::Undefined)
+}
+
 /// `domainMemory` property setter
 pub fn set_domain_memory<'gc>(
     activation: &mut Activation<'_, 'gc>,