diff --git a/requirements.txt b/requirements.txt
index 26077a079..b42839c2c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -15,6 +15,6 @@ ufo2ft==3.3.0
 pyobjc==10.3.1; sys_platform == "darwin"
 freetype-py==2.5.1
 uharfbuzz==0.41.0
-glyphsLib==6.8.0 # this is only required to run Tests/varLib/interpolatable_test.py
+glyphsLib==6.9.0 # this is only required to run Tests/varLib/interpolatable_test.py
 lxml==5.3.0
 sympy==1.13.2