diff --git a/default_conf.py b/default_conf.py
index c92d42a..96ce509 100644
--- a/default_conf.py
+++ b/default_conf.py
@@ -22,7 +22,7 @@ DB_FILENAME = 'iwla.db'
 # Web server log format (nginx style). Default is apache log format
 log_format = '$server_name:$server_port $remote_addr - $remote_user [$time_local] ' +\
     '"$request" $status $body_bytes_sent ' +\
-    '"$http_referer" "$http_user_agent"'
+    '"$http_referer?" "$http_user_agent?"'
 
 # Time format used in log format
 time_format = '%d/%b/%Y:%H:%M:%S %z'
diff --git a/iwla.py b/iwla.py
index 8211032..a2ed3de 100755
--- a/iwla.py
+++ b/iwla.py
@@ -143,7 +143,7 @@ class IWLA(object):
         self.valid_visitors = None
         self.dry_run = dry_run
 
-        self.log_format_extracted = re.sub(r'([^\$\w])', r'\\\g<1>', conf.log_format)
+        self.log_format_extracted = re.sub(r'([^\$?\w])', r'\\\g<1>', conf.log_format)
         self.log_format_extracted = re.sub(r'\$(\w+)', '(?P<\g<1>>.+)', self.log_format_extracted)
         self.http_request_extracted = re.compile(r'(?P<http_method>\S+) (?P<http_uri>\S+) (?P<http_version>\S+)')
         self.log_re = re.compile(self.log_format_extracted)
@@ -374,10 +374,10 @@ class IWLA(object):
         groups = self.http_request_extracted.match(hit['request'])
 
         if groups:
-            hit['extract_request'] = groups.groupdict()
+            hit['extract_request'] = groups.groupdict("")
             uri_groups = self.uri_re.match(hit['extract_request']['http_uri'])
             if uri_groups:
-                d = uri_groups.groupdict()
+                d = uri_groups.groupdict("")
                 hit['extract_request']['extract_uri'] = self._normalizeURI(d['extract_uri'])
                 if 'extract_parameters' in d.keys():
                     parameters = self._normalizeParameters(d['extract_parameters'])
@@ -390,7 +390,7 @@ class IWLA(object):
         if hit['http_referer']:
             referer_groups = self.uri_re.match(hit['http_referer'])
             if referer_groups:
-                hit['extract_referer'] = referer_groups.groupdict()
+                hit['extract_referer'] = referer_groups.groupdict("")
                 hit['extract_referer']['extract_uri'] = self._removeFinalSlashes(hit['extract_referer']['extract_uri'])
                 hit['extract_referer']['extract_parameters'] = self._normalizeParameters(hit['extract_referer']['extract_parameters'])
         return True
@@ -781,7 +781,7 @@ class IWLA(object):
             groups = self.log_re.match(l)
 
             if groups:
-                self._newHit(groups.groupdict())
+                self._newHit(groups.groupdict(""))
             else:
                 self.logger.warning("No match for %s" % (l))
                 #break