diff --git a/mosaic/libmosaic/analyzer/abstract_syntax_analyzer.py b/mosaic/libmosaic/analyzer/abstract_syntax_analyzer.py
index f537938..ba0d006 100644
--- a/mosaic/libmosaic/analyzer/abstract_syntax_analyzer.py
+++ b/mosaic/libmosaic/analyzer/abstract_syntax_analyzer.py
@@ -101,7 +101,7 @@ def _parse(self):
             elif isinstance(node, ast.FunctionDef):
                 self._process_function(node, parent_class=None)
 
-    def _process_class(self, class_node: ast.ClassDef):
+    def _process_class(self, class_node: ast.ClassDef) -> None:
         """Process a class and its methods."""
         class_name = class_node.name
         start_line = class_node.lineno  # AST uses 1-based indexing