diff --git a/emerging_optimizers/utils/eig.py b/emerging_optimizers/utils/eig.py
index 9918df1..439ef4a 100644
--- a/emerging_optimizers/utils/eig.py
+++ b/emerging_optimizers/utils/eig.py
@@ -140,6 +140,7 @@ def eig_orthogonal_iteration(
     Q = approx_eigenvectors
     approx_eigvals = conjugate(x, Q, diag=True)
     iteration = 0
+    sorted_approx_eigvals: Tensor = approx_eigvals
     while iteration < max_iterations and not met_approx_eigvals_criteria(x, approx_eigvals, tolerance):
         power_iteration = x @ Q
         Q = torch.linalg.qr(power_iteration).Q
diff --git a/mypy.ini b/mypy.ini
new file mode 100644
index 0000000..d3d2530
--- /dev/null
+++ b/mypy.ini
@@ -0,0 +1,25 @@
+[mypy]
+cache_dir = .mypy_cache/normal
+allow_redefinition = True
+warn_unused_configs = True
+warn_redundant_casts = True
+show_error_codes = True
+show_column_numbers = True
+check_untyped_defs = True
+disallow_untyped_defs = True
+disallow_untyped_decorators = True
+follow_imports = normal
+local_partial_types = True
+enable_error_code = possibly-undefined
+
+# do not reenable this:
+# https://github.com/pytorch/pytorch/pull/60006#issuecomment-866130657
+warn_unused_ignores = False
+
+ignore_missing_imports = True
+
+files =
+    emerging_optimizers,
+    
+
+exclude = ^docs
\ No newline at end of file