diff --git a/requirements.txt b/requirements.txt
index e6b0a23..fec7bb6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,4 +8,5 @@ Shapely
 
 # Packaging
 setuptools>=40.6.3
-wheel>=0.32.3
\ No newline at end of file
+wheel>=0.32.3
+fonttools>=4.43.0 # not directly required, pinned by Snyk to avoid a vulnerability
\ No newline at end of file