diff --git a/requirements.txt b/requirements.txt
index 1b5c354..d16e993 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-bottle==0.12.13
+bottle==0.12.20
 mpmath==1.0.0
 numpy==1.13.3
 scipy==1.0.0