diff --git a/requirements.txt b/requirements.txt
index 88e45ef..1b5b89b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -48,7 +48,7 @@ prompt-toolkit==1.0.15
 protobuf==3.6.0
 ptyprocess==0.6.0
 pydicom==1.1.0
-Pygments==2.2.0
+Pygments==2.7.4
 pynrrd==0.2.4
 pyparsing==2.2.0
 python-dateutil==2.7.3