diff --git a/pytransifex/api.py b/pytransifex/api.py
index 201121f..3d71c54 100644
--- a/pytransifex/api.py
+++ b/pytransifex/api.py
@@ -229,33 +229,15 @@ def get_translation(
             )
 
     @ensure_login
-    def list_languages(self, project_slug: str, resource_slug: str) -> list[str]:
+    def list_languages(self, project_slug: str) -> list[str]:
         """
         List languages for which there exist translations under the given resource.
         """
         if self.projects:
             if project := self.projects.get(slug=project_slug):
-                if resource := project.fetch("resources").get(slug=resource_slug):
-                    it = tx_api.ResourceLanguageStats.filter(
-                        project=project, resource=resource
-                    ).all()
-
-                    language_codes = []
-                    for tr in it:
-                        """
-                        FIXME
-                        This is hideous and probably unsound for some language_codes.
-                        Couldn't find a more direct accessor to language codes.
-                        """
-                        code = str(tr).rsplit("_", 1)[-1][:-1]
-                        language_codes.append(code)
-
-                    logger.info(f"Obtained these languages: {language_codes}")
-                    return language_codes
+                languages = project.fetch("languages").all()
+                return [lang.code for lang in languages]
 
-                raise ValueError(
-                    f"Unable to find any resource with this slug: '{resource_slug}'"
-                )
             raise ValueError(
                 f"Unable to find any project with this slug: '{project_slug}'"
             )
diff --git a/pytransifex/interfaces.py b/pytransifex/interfaces.py
index 8268dd3..efc4a0e 100644
--- a/pytransifex/interfaces.py
+++ b/pytransifex/interfaces.py
@@ -61,7 +61,7 @@ def get_translation(
         raise NotImplementedError
 
     @abstractmethod
-    def list_languages(self, project_slug: str, resource_slug: str) -> list[Any]:
+    def list_languages(self, project_slug: str) -> list[Any]:
         raise NotImplementedError
 
     @abstractmethod
diff --git a/tests/test_api.py b/tests/test_api.py
index 6e03ecb..3c661cc 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -77,9 +77,7 @@ def test6_create_language(self):
         self.tx.create_language(project_slug=self.project_slug, language_code="fr_CH")
 
     def test7_list_languages(self):
-        languages = self.tx.list_languages(
-            project_slug=self.project_slug, resource_slug=self.resource_slug
-        )
+        languages = self.tx.list_languages(project_slug=self.project_slug)
         logger.info(f"Languages found: {languages}")
         assert languages