diff --git a/tools/config.py b/tools/config.py
index b3a64c6547..d00bfc7d2f 100644
--- a/tools/config.py
+++ b/tools/config.py
@@ -396,7 +396,7 @@ class Config(object):
 
         self.cumulative_overrides = {key: ConfigCumulativeOverride(key)
                                      for key in
-                                     Target._Target__cumulative_attributes}
+                                     Target.cumulative_attributes}
 
         self._process_config_and_overrides(self.app_config_data, {}, "app",
                                            "application")
diff --git a/tools/targets.py b/tools/targets.py
index 1a2c3b5481..e81bf50763 100644
--- a/tools/targets.py
+++ b/tools/targets.py
@@ -59,7 +59,7 @@ def cached(func):
 class Target:
     # Cumulative attributes can have values appended to them, so they
     # need to be computed differently than regular attributes
-    __cumulative_attributes = ['extra_labels', 'macros', 'device_has', 'features']
+    cumulative_attributes = ['extra_labels', 'macros', 'device_has', 'features']
 
     # List of targets that were added dynamically using "add_py_targets" (see below)
     __py_targets = set()