diff --git a/requirements-dev.txt b/requirements-dev.txt
index 3b7410c8..04530ff8 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -9,7 +9,7 @@ charset-normalizer==3.4.4 ; python_version >= "3.11" and python_version < "3.15"
 colorama==0.4.6 ; python_version >= "3.11" and python_version < "3.15" and (sys_platform == "win32" or platform_system == "Windows")
 contourpy==1.3.3 ; python_version >= "3.11" and python_version < "3.15"
 cycler==0.12.1 ; python_version >= "3.11" and python_version < "3.15"
-filelock==3.20.3 ; python_version >= "3.11" and python_version < "3.15"
+filelock==3.21.2 ; python_version >= "3.11" and python_version < "3.15"
 fonttools==4.61.1 ; python_version >= "3.11" and python_version < "3.15"
 fsspec==2026.1.0 ; python_version >= "3.11" and python_version < "3.15"
 healpy==1.19.0 ; python_version >= "3.11" and python_version < "3.15"