diff --git a/src/bayesvalidrox/pylink/pylink.py b/src/bayesvalidrox/pylink/pylink.py
index 1a591d30cbad4f767884d5cf77c5d7fc72e20bfe..f88bf266222d0a612f2d89db03e2f81696995818 100644
--- a/src/bayesvalidrox/pylink/pylink.py
+++ b/src/bayesvalidrox/pylink/pylink.py
@@ -456,7 +456,7 @@ class PyLinkForwardModel(object):
                 group_results = Function(c_points)
             else:
                 group_results = self.run_forwardmodel(
-                    c_points, prevRun_No, key_str
+                    (c_points, prevRun_No, key_str)
                     )
 
         elif self.multi_process or mp: