diff --git a/peppy/_version.py b/peppy/_version.py
index da532ef5..4bbef18e 100644
--- a/peppy/_version.py
+++ b/peppy/_version.py
@@ -1 +1 @@
-__version__ = "0.40.0a3"
+__version__ = "0.40.0a4"
diff --git a/peppy/project.py b/peppy/project.py
index 090d37ed..ccdc7f04 100644
--- a/peppy/project.py
+++ b/peppy/project.py
@@ -255,7 +255,7 @@ def to_dict(
                 SUBSAMPLE_RAW_LIST_KEY: sub_df,
             }
         else:
-            p_dict = self.config
+            p_dict = self.config.copy()
             p_dict["_samples"] = [s.to_dict() for s in self.samples]
 
         return p_dict