diff --git a/pyproject.toml b/pyproject.toml
index e32857c..c0d08fa 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -35,7 +35,7 @@ zulip = [
 tests = [
     "pytest>=7.4.4,<8.4.0",
     "types-PyYAML~=6.0.12",
-    "mypy>=1.8,<1.12",
+    "mypy>=1.8,<1.20",
     "zulip~=0.9.0"
 ]