diff --git a/pyproject.toml b/pyproject.toml
index f2c6552b..42974277 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -52,7 +52,7 @@ dependencies = [
 [project.optional-dependencies]
 dev = [
     "black==26.5.1",
-    "pydoclint==0.8.5",
+    "pydoclint==0.9.0",
     "flake8==7.3.0",
 ]
 docs = [
diff --git a/requirements.txt b/requirements.txt
index a611d25d..caa6008b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,7 +2,7 @@ ortools==9.15.6755
 sympy==1.14.0
 unicorn==2.1.4
 black==26.5.1
-pydoclint==0.8.5
+pydoclint==0.9.0
 flake8==7.3.0
 
 # Optional dependencies for documentation (only for Python >= 3.11)