diff --git a/abcvoting/fileio.py b/abcvoting/fileio.py
index 47d9093..1d33dbe 100644
--- a/abcvoting/fileio.py
+++ b/abcvoting/fileio.py
@@ -202,7 +202,7 @@ def read_preflib_files_from_dir(dir_name, top_ranks=None, setsize=None):
     return profiles
 
 
-def write_profile_to_preflib_cat_file(filename, profile):
+def write_profile_to_preflib_cat_file(filepath, profile):
     """
     Write a profile to a Preflib category file (.cat).
 
@@ -219,9 +219,10 @@ def write_profile_to_preflib_cat_file(filename, profile):
         None
     """
     preflib_inst = preflib.CategoricalInstance()
+    preflib_inst.data_type = "cat"
     preflib_inst.num_categories = 2
     preflib_inst.categories_name = {"1": "Approved", "2": "Not approved"}
-    preflib_inst.file_name = filename
+    preflib_inst.file_name = os.path.basename(filepath)
     preflib_inst.num_alternatives = profile.num_cand
     for cand in profile.candidates:
         preflib_inst.alternatives_name[cand + 1] = profile.cand_names[cand]
@@ -241,7 +242,7 @@ def write_profile_to_preflib_cat_file(filename, profile):
         else:
             preflib_inst.multiplicity[pref] += multiplicity
     preflib_inst.recompute_cardinality_param()
-    preflib_inst.write(filename)
+    preflib_inst.write(filepath)
 
 
 def _yaml_flow_style_list(x):
diff --git a/examples/preflib-files/new_example.cat b/examples/preflib-files/new_example.cat
index d41ccc7..1abb2e2 100644
--- a/examples/preflib-files/new_example.cat
+++ b/examples/preflib-files/new_example.cat
@@ -1,4 +1,4 @@
-# FILE NAME: C:\Users\reysi\PycharmProjects\abcvoting\examples\preflib-files/new_example.cat
+# FILE NAME: new_example.cat
 # TITLE: 
 # DESCRIPTION: 
 # DATA TYPE: cat
diff --git a/tests/data/test5.cat b/tests/data/test5.cat
index 4a82fce..135d23d 100644
--- a/tests/data/test5.cat
+++ b/tests/data/test5.cat
@@ -1,4 +1,4 @@
-# FILE NAME: C:\Users\reysi\PycharmProjects\abcvoting\tests/data/test5.cat
+# FILE NAME: test5.cat
 # TITLE: 
 # DESCRIPTION: 
 # DATA TYPE: cat