diff --git a/pyproject.toml b/pyproject.toml
index 49d6c52..82475e1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,7 +31,7 @@ dev = [
     "pytest>=7.0.0",
     "pytest-cov>=4.0.0",
     "ruff~=0.15.0",
-    "mypy~=1.20.0",
+    "mypy>=1.20,<2.1",
     "psutil>=5.9.0",
     "pre-commit>=3.5.0",
 ]
diff --git a/uv.lock b/uv.lock
index 0f49b2a..9874292 100644
--- a/uv.lock
+++ b/uv.lock
@@ -2475,7 +2475,7 @@ requires-dist = [
     { name = "ipywidgets", marker = "extra == 'notebook'", specifier = ">=8.1.8" },
     { name = "jupyterlab", marker = "extra == 'notebook'", specifier = ">=4.5.7" },
     { name = "matplotlib", marker = "extra == 'analysis'", specifier = ">=3.7.0" },
-    { name = "mypy", marker = "extra == 'dev'", specifier = "~=1.20.0" },
+    { name = "mypy", marker = "extra == 'dev'", specifier = ">=1.20,<2.1" },
     { name = "numpy", specifier = ">=1.24.0" },
     { name = "ordpy", marker = "extra == 'notebook'", specifier = ">=1.2.2" },
     { name = "packaging", specifier = ">=21.0" },