diff --git a/tests/ooxml/test_basic.py b/tests/ooxml/test_basic.py
index f668aa0..f25d7f4 100644
--- a/tests/ooxml/test_basic.py
+++ b/tests/ooxml/test_basic.py
@@ -12,24 +12,33 @@ from oletools import ooxml
 class TestOOXML(unittest.TestCase):
     """ Tests my cool new feature """
 
+    DO_DEBUG = False
+
     def test_all_rough(self):
         """Checks all samples, expect either ole files or good ooxml output"""
         acceptable = ooxml.DOCTYPE_EXCEL, ooxml.DOCTYPE_WORD, \
                      ooxml.DOCTYPE_POWERPOINT
+
+        # files that are neither OLE nor xml:
         except_files = 'empty', 'text'
-        except_extns = '.xml', '.rtf'
+        except_extns = '.xml', '.rtf', '.csv'
+
+        # analyse all files in data dir
         for base_dir, _, files in os.walk(DATA_BASE_DIR):
             for filename in files:
                 if filename in except_files:
-                    #print('skip file: ' + filename)
+                    if self.DO_DEBUG:
+                        print('skip file: ' + filename)
                     continue
                 if splitext(filename)[1] in except_extns:
-                    #print('skip extn: ' + filename)
+                    if self.DO_DEBUG:
+                        print('skip extn: ' + filename)
                     continue
 
                 full_name = join(base_dir, filename)
                 if isOleFile(full_name):
-                    #print('skip ole: ' + filename)
+                    if self.DO_DEBUG:
+                        print('skip ole: ' + filename)
                     continue
                 try:
                     doctype = ooxml.get_type(full_name)
@@ -38,7 +47,8 @@ class TestOOXML(unittest.TestCase):
                 self.assertTrue(doctype in acceptable,
                                 msg='Doctype "{0}" for {1} not acceptable'
                                     .format(doctype, full_name))
-                #print('ok: ' + filename + doctype)
+                if self.DO_DEBUG:
+                    print('ok: {0} --> {1}'.format(filename, doctype))
 
 
 # just in case somebody calls this file as a script