diff --git a/.gitignore b/.gitignore
index 5ebd21a1..90f38e8d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -161,3 +161,5 @@ pip-log.txt
 
 # Mac crap
 .DS_Store
+*.log
+
diff --git a/jieba/__init__.py b/jieba/__init__.py
index 62185aac..50067059 100644
--- a/jieba/__init__.py
+++ b/jieba/__init__.py
@@ -252,3 +252,10 @@ def pcut_for_search(sentence):
 	cut = pcut
 	cut_for_search = pcut_for_search
 
+def disable_parallel():
+	global pool,cut,cut_for_search
+	if pool != None:
+		pool.close()
+		pool = None
+	cut = __ref_cut
+	cut_for_search = __ref_cut_for_search
diff --git a/jieba/posseg/__init__.py b/jieba/posseg/__init__.py
index 8e265aaf..41e650d5 100644
--- a/jieba/posseg/__init__.py
+++ b/jieba/posseg/__init__.py
@@ -151,7 +151,7 @@ def __lcut_internal(sentence):
 	return list(__cut_internal(sentence))
 
 def cut(sentence):
-	if not hasattr(jieba,'pool'):
+	if (not hasattr(jieba,'pool')) or (jieba.pool==None):
 		for w in __cut_internal(sentence):
 			yield w
 	else: