diff --git a/capa/features/extractors/base_extractor.py b/capa/features/extractors/base_extractor.py
index c3d04736..5724e628 100644
--- a/capa/features/extractors/base_extractor.py
+++ b/capa/features/extractors/base_extractor.py
@@ -274,6 +274,7 @@ class ProcessHandle:
         inner: sandbox-specific data
     """
 
+    ppid: int
     pid: int
     inner: Any