diff --git a/requirements.txt b/requirements.txt
index b45e408..92b2c37 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,10 +1,10 @@
-arrow
-decorator
+arrow==0.9.0
+decorator==4.0.10
 praw==3.6.0
-PyYAML
-requests
-six
+PyYAML==3.12
+requests==2.12.1
+six==1.10.0
 backports-abc==0.4
 tornado==4.3
-update-checker==0.11
+update-checker==0.15
 wheel==0.24.0