diff --git a/requirements-dev.txt b/requirements-dev.txt
index 532fc6d..7d00aa4 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,7 +1,7 @@
 # Developer tooling for the Python training/export utilities (tools/).
 # Runtime training deps are in requirements.txt.
 ruff>=0.17.1,<0.18
-mypy>=1.19,<2
+mypy>=2.4.0,<3
 pytest>=8,<9
 # Chess legality comes from ChessEngine-validator; feature encoding uses
 # FEN decoding in tools/nnue/halfka_features.py.