diff --git a/pyproject.toml b/pyproject.toml
index 2edbadefc..5ee6894de 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,7 +5,7 @@ requires = [
     "cymem>=2.0.2,<2.1.0",
     "preshed>=3.0.2,<3.1.0",
     "murmurhash>=0.28.0,<1.1.0",
-    "thinc>=8.3.0,<8.4.0",
+    "thinc>=9.1.0,<10.0.0",
     "numpy>=2.0.0,<2.1.0; python_version < '3.9'",
     "numpy>=2.0.0,<2.1.0; python_version >= '3.9'",
 ]