diff --git a/generate.py b/generate.py
index fe4b464..24b4e39 100755
--- a/generate.py
+++ b/generate.py
@@ -75,7 +75,7 @@ def main():
     parser.add_argument('description', type=str, nargs='+', help='file containing the taskset description.')
     parser.add_argument('--header', dest='header', type=str, nargs='?', default='./template/config.h', help='path to optional custom header file.')
     parser.add_argument('--makefile', dest='makefile', type=str, nargs='?', default='./template/Makefile', help='path to optional custom makefile.')
-    parser.add_argument('--cpp', dest='cpp', type=str, nargs='?', default='./template/experiment.cpp', help='path to optional custom c++ implementation.')
+    parser.add_argument('--cpp', dest='cpp', type=str, nargs='*', default='./template/experiment.cpp', help='path to optional custom c++ implementation.')
 
     args = parser.parse_args()
     cwd = os.getcwd()