diff --git a/requirements-ci.in b/requirements-ci.in
index 6fc6380f..1eac516c 100644
--- a/requirements-ci.in
+++ b/requirements-ci.in
@@ -9,7 +9,7 @@ flake8==7.3.0
 black==26.3.1
 mypy==1.20.2
 bandit==1.9.4
-build==1.4.4
+build==1.5.0
 atheris==3.0.0
 python-afl==0.7.3
 pip-audit==2.10.0
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 2a36e54c..e70d3b82 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -10,7 +10,7 @@ tox>=4.6.0
 sphinx>=7.1.0
 sphinx-rtd-theme>=1.3.0
 twine>=4.0.0
-build>=1.4.4
+build>=1.5.0
 
 # Property-based testing (security invariant verification)
 hypothesis>=6.100.0,<6.153.0  # Pinned to avoid types.SimpleNamespace bug in 6.123+