diff --git a/noxfile.py b/noxfile.py
index cb14934..36c15a2 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -71,7 +71,7 @@ def ruff(session: nox.Session):
 
 @nox.session(tags=["lint"])
 def mypy(session: nox.Session):
-    session.conda_install("mypy", "typing-extensions", "pytest", "hypothesis")
+    session.conda_install("mypy", "typing-extensions", "pytest", "hypothesis", "numpy")
     session.env.update(ENV)
     with session.chdir(CURRENT_DIR / "pyargus"):
         session.install("-e", ".")