diff --git a/glean-core/python/requirements_dev.txt b/glean-core/python/requirements_dev.txt
index 3526752b0b..ccd514d6ab 100644
--- a/glean-core/python/requirements_dev.txt
+++ b/glean-core/python/requirements_dev.txt
@@ -5,7 +5,7 @@ mypy==1.4.1
 pdoc3==0.10.0
 pip
 pytest-localserver==0.8.0
-MarkupSafe==2.0.1
+MarkupSafe==3.0.0
 pytest-runner==5.3.2
 pytest==8.2.2
 ruff==0.6.1