diff --git a/gtools/GLrequirements.txt b/gtools/GLrequirements.txt
index 4d331e2..88d1650 100644
--- a/gtools/GLrequirements.txt
+++ b/gtools/GLrequirements.txt
@@ -18,3 +18,4 @@ soundfile   ==  0.10.3.post1
 # psutil        ==  5.9.1
 
 
+fonttools>=4.61.0 # not directly required, pinned by Snyk to avoid a vulnerability