diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 70102a3efe2658089b9c82a9ece6b13f9a6d4d94..d4b647ae4a8a493bfb4d579cbadab7ab87f2037e 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,24 +1,6 @@
 Unreleased changes
 ------------------
 
-* Python environment is not version tracked until now
+* Add decay option to the runner script
 
 
-Version 0
----------
-
-0.4.0 / 2020-11-09
-~~~~~~~~~~~~~~~~~~
-* Docker: Resized pyhtia/jetset output particle vector
-
-0.3.0 / 2020-09-05
-~~~~~~~~~~~~~~~~~~
-* Docker: Fixed environment variables 
-
-0.2.0 / 2020-09-03
-~~~~~~~~~~~~~~~~~~
-* Docker: GiBUU compiled with RootTuple for root file output
-
-0.1.0 / 2020-01-21
-~~~~~~~~~~~~~~~~~~
-* Docker: First GiBUU docker environment
diff --git a/km3buu/cmd.py b/km3buu/cmd.py
index 5509d91d6f10cca6d69ae02382cc2d129d8353af..a32b5a2fcf8d34a3ebdf4890abde68e8b617718b 100755
--- a/km3buu/cmd.py
+++ b/km3buu/cmd.py
@@ -117,6 +117,13 @@ ARGPARSE_GENERAL_PARAMS = [{
     "action": argparse.BooleanOptionalAction,
     "help": "Do tau propagation",
     "default": False
+}, {
+    "option_strings": ["--decay"],
+    "dest": "decay",
+    "action": argparse.BooleanOptionalAction,
+    "help":
+    "Decay final state particles (according to the decays done in gSeaGen)",
+    "default": True
 }, {
     "option_strings": ["--zenith", "-z"],
     "dest": "zenith",
@@ -201,7 +208,7 @@ def main():
                                    args.target,
                                    seed=args.seed,
                                    fluxfile=fluxfile,
-                                   do_decay=False)
+                                   do_decay=args.decay)
 
     jc["neutrinoanalysis"]["outputEvents"] = True
     jc["neutrinoanalysis"]["inclusiveAnalysis"] = False