diff --git a/README.md b/README.md
index 9f3b216..082a1f3 100644
--- a/README.md
+++ b/README.md
@@ -314,6 +314,7 @@ export THEFUCK_REQUIRE_CONFIRMATION='true'
 export THEFUCK_WAIT_COMMAND=10
 export THEFUCK_NO_COLORS='false'
 export THEFUCK_PRIORITY='no_command=9999:apt_get=100'
+export THEFUCK_HISTORY_LIMIT='2000'
 ```
 
 ## Developing
diff --git a/thefuck/conf.py b/thefuck/conf.py
index 47eaf34..21a1775 100644
--- a/thefuck/conf.py
+++ b/thefuck/conf.py
@@ -16,6 +16,7 @@ DEFAULT_SETTINGS = {'rules': DEFAULT_RULES,
                     'no_colors': False,
                     'debug': False,
                     'priority': {},
+                    'history_limit': None,
                     'env': {'LC_ALL': 'C', 'LANG': 'C', 'GIT_TRACE': '1'}}
 
 ENV_TO_ATTR = {'THEFUCK_RULES': 'rules',
@@ -126,4 +127,3 @@ class Settings(dict):
 
 
 settings = Settings(DEFAULT_SETTINGS)
-settings.init()
diff --git a/thefuck/shells.py b/thefuck/shells.py
index d82a88b..a703780 100644
--- a/thefuck/shells.py
+++ b/thefuck/shells.py
@@ -60,10 +60,10 @@ class Generic(object):
 
     def get_history(self):
         """Returns list of history entries."""
-        tail_num = settings.get("history_limit", None)
+        tail_num = settings.history_limit
         history_file_name = self._get_history_file_name()
         if os.path.isfile(history_file_name):
-            if tail_num is not None:
+            if tail_num is not None and tail_num.isdigit():
                 _, f = os.popen2("tail -n {} {}".format(tail_num, history_file_name))
                 _.close()
             else: