diff --git a/requirements.txt b/requirements.txt
index b4853fd..332b315 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,4 +4,4 @@
 #
 #    pip-compile
 #
-fonttools==4.38.0         # via dehinter (setup.py)
+fonttools==4.39.4         # via dehinter (setup.py)