diff --git a/README.md b/README.md
index ab11f2f..3b893e4 100644
--- a/README.md
+++ b/README.md
@@ -119,7 +119,7 @@ GNU AGPLv3 code
 
 Further options:
 - Change what morss does
-- `debug`: to have some feedback from the script execution. Useful for debugging. NB. for cli use, set the environment variable `DEBUG=1`
+- Environment variable `DEBUG=`: to have some feedback from the script execution. Useful for debugging. On Apache, can be set via the `SetEnv` instruction
 - `silent`: don't output the final RSS (useless on its own, but can be nice when debugging)
 - `callback=NAME`: for JSONP calls
 - `cors`: allow Cross-origin resource sharing (allows XHR calls from other servers)
diff --git a/morss/cgi.py b/morss/cgi.py
index 68c891a..47d727d 100644
--- a/morss/cgi.py
+++ b/morss/cgi.py
@@ -39,8 +39,11 @@ def cgi_parse_environ(environ):
     # get options
 
     if 'REQUEST_URI' in environ:
+        # when running on Apache
         url = environ['REQUEST_URI'][1:]
+
     else:
+        # when using internal server
         url = environ['PATH_INFO'][1:]
 
         if environ['QUERY_STRING']:
diff --git a/morss/morss.py b/morss/morss.py
index ac207d9..e6ffd74 100644
--- a/morss/morss.py
+++ b/morss/morss.py
@@ -39,14 +39,13 @@ class MorssException(Exception):
 
 
 def log(txt):
-    if ('DEBUG' in os.environ
-            or ':debug' in os.environ.get('REQUEST_URI', '')
-            or ':debug' in os.environ.get('PATH_INFO', '')
-            ):
+    if 'DEBUG' in os.environ:
         if 'REQUEST_URI' in os.environ:
+            # when running on Apache
             open('morss.log', 'a').write("%s\n" % repr(txt))
 
         else:
+            # when using internal server or cli
             print(repr(txt))