diff --git a/requirements.txt b/requirements.txt
index c16df62..57bab90 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -27,7 +27,7 @@ click==8.1.7
     # via
     #   volare
     #   yowasp-yosys
-cocotb==1.8.1
+cocotb==1.9.1
     # via tt-support-tools (pyproject.toml)
 cssselect2==0.7.0
     # via cairosvg