diff --git a/pyproject.toml b/pyproject.toml
index 9774a98..978afa0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -29,7 +29,7 @@ dev = [
   "pytest-xdist==3.6.1",
   "pytest-sugar==1.0.0",
   "pytest-codspeed",
-  "diff-cover==9.0.0",
+  "diff-cover==9.1.1",
   "ruff==0.4.4",
 ]
 
@@ -43,7 +43,7 @@ rye = { dev-dependencies = [
   "pytest-xdist==3.6.1",
   "pytest-sugar==1.0.0",
   "pytest-codspeed>=2.2.0",
-  "diff-cover==9.0.0",
+  "diff-cover==9.1.1",
   "ruff==0.4.4",
 ] }