diff --git a/vcsserver/http_main.py b/vcsserver/http_main.py
--- a/vcsserver/http_main.py
+++ b/vcsserver/http_main.py
@@ -144,7 +144,7 @@ class VCS(object):
 
     def _configure_locale(self):
         if self.locale:
-            log.info('Settings locale: `LC_ALL` to %s' % self.locale)
+            log.info('Settings locale: `LC_ALL` to %s', self.locale)
         else:
             log.info(
                 'Configuring locale subsystem based on environment variables')
diff --git a/vcsserver/lib/memory_lru_dict.py b/vcsserver/lib/memory_lru_dict.py
--- a/vcsserver/lib/memory_lru_dict.py
+++ b/vcsserver/lib/memory_lru_dict.py
@@ -58,7 +58,7 @@ class LRUDictDebug(LRUDict):
         fmt = '\n'
         for cnt, elem in enumerate(self.keys()):
             fmt += '%s - %s\n' % (cnt+1, safe_str(elem))
-        log.debug('current LRU keys (%s):%s' % (elems_cnt, fmt))
+        log.debug('current LRU keys (%s):%s', elems_cnt, fmt)
 
     def __getitem__(self, key):
         self._report_keys()
diff --git a/vcsserver/tweens.py b/vcsserver/tweens.py
--- a/vcsserver/tweens.py
+++ b/vcsserver/tweens.py
@@ -46,10 +46,8 @@ class RequestWrapperTween(object):
         finally:
             end = time.time()
 
-            log.info('IP: %s Request to path: `%s` time: %.3fs' % (
-                '127.0.0.1',
-                safe_str(get_access_path(request)), end - start)
-            )
+            log.info('IP: %s Request to path: `%s` time: %.3fs',
+                     '127.0.0.1', safe_str(get_access_path(request)), end - start)
 
         return response