diff --git a/binarycpython/utils/HPC.py b/binarycpython/utils/HPC.py
index 9220a23cbd5ad3129c40c467b73b8ba50822329f..ace9f8dae3a7a39d5f4692b3eeb093c21bddfcdb 100644
--- a/binarycpython/utils/HPC.py
+++ b/binarycpython/utils/HPC.py
@@ -21,13 +21,19 @@ class HPC(condor,slurm):
         # don't do anything: we just inherit from this class
         return
 
-    def HPC_joinfiles(self):
+    def HPC_joinfiles(self,joinlist=None):
         """
         Function to load in the joinlist to a list and return it.
         """
-        f = open(self.grid_options['joinlist'],'r',encoding='utf-8')
-        list = f.read().splitlines()
-        f.close()
+        if joinlist is None:
+            joinlist = self.grid_options['joinlist']
+        f = open(joinlist,'r',encoding='utf-8')
+        if f:
+            list = f.read().splitlines()
+            f.close()
+        else:
+            print("Failed to open joinlist at {list}".format(list=joinlist))
+            self.exit(code=1)
         return list
 
     def HPC_join_from_files(self,newobj,joinfiles):