diff --git a/requirements.txt b/requirements.txt
index 8b481fd..6e10902 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -55,7 +55,7 @@ pomegranate==0.9.0
 prompt-toolkit==1.0.15
 ptyprocess==0.5.2
 pycosat==0.6.3
-Pygments==2.2.0
+Pygments==2.7.4
 pymc3==3.4.1
 pyparsing==2.2.0
 python-dateutil==2.7.2