diff --git a/src/condor.erl b/src/condor.erl
index ff77041..0863a4d 100644
--- a/src/condor.erl
+++ b/src/condor.erl
@@ -152,3 +152,21 @@ format_submit(CondorParams0) ->
   SubmitFileStr = maps:fold(fun(K, V, Acc) -> [Acc, io_lib:format("~p = ~s", [K,V]), LineSep] end, "", CondorParams1),
   iolist_to_binary([LineSep, lists:flatten(SubmitFileStr), LineSep, "Queue", LineSep]).
 
+%% @doc Converts the transfer_input_files field from a Condor submit map to a
+%%      comma-separated string.
+%%
+%%      The only parameter that might come here as a list instead of complete
+%%      cs-string is transfer_input_files because it might be generated by
+%%      Cuneiform and it needs file validation. Therefore any declared
+%%      transfer_input_files params need to be first parsed from cs-string
+%%      into a list, and once they are validated and possibly merged, they are
+%%      converted back to cs-string here.
+%%
+-spec input_files_to_cs_string( CondorParams ) -> #{atom() => string()}
+when CondorParams :: #{atom() => string() | [string()]}.
+
+input_files_to_cs_string(#{transfer_input_files := InputFiles} = CondorParams) ->
+  InputFilesCS = string:join(InputFiles, ", "),
+  maps:put(transfer_input_files, InputFilesCS, CondorParams);
+
+input_files_to_cs_string(CondorParams) -> CondorParams.
\ No newline at end of file