diff --git a/VertebralColumn_KNN/requirements.txt b/VertebralColumn_KNN/requirements.txt
index 2c6a81b..e55c692 100644
--- a/VertebralColumn_KNN/requirements.txt
+++ b/VertebralColumn_KNN/requirements.txt
@@ -66,7 +66,7 @@ pycosat==0.6.3
 pycparser==2.18
 pygame==1.9.4
 pyglet==1.3.2
-Pygments==2.2.0
+Pygments==2.7.4
 pyOpenSSL==18.0.0
 pyparsing==2.2.0
 PySocks==1.6.8