diff --git a/requirements-test.txt b/requirements-test.txt
index 2e315dd..473c1c3 100644
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -3,5 +3,5 @@ jupyterlab ~= 3.5.0
 nbconvert ~= 7.2.5
 
 # Type checking.
-mypy ~= 0.991
+mypy ~= 1.9.0
 pytype ~= 2024.3.19