diff --git a/requirements.txt b/requirements.txt
index 184af376..7e96b720 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,4 +7,4 @@ raven>=5.23.0
 psutil>=3.0.0
 zipstream>=1.1.4
 typing>=3.5.3.0 # Otherwise yarl fails with python 3.4
-prompt-toolkit
+prompt-toolkit==1.0.15