diff --git a/Cargo.lock b/Cargo.lock
index 74c087a..b485aa5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -463,9 +463,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.20.2"
+version = "1.21.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1261fe7e33c73b354eab43b1273a57c8f967d0391e80353e51f764ac02cf6775"
+checksum = "d75b0bedcc4fe52caa0e03d9f1151a323e4aa5e2d78ba3580400cd3c9e2bc4bc"
 dependencies = [
  "critical-section",
  "portable-atomic",
diff --git a/Cargo.toml b/Cargo.toml
index 906a3bf..c242602 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -34,7 +34,7 @@ embedded-io-async = "0.6.1"
 mqttrs = { version = "0.4.1", default-features = false }
 heapless = "0.7.0"
 embedded-io = "0.6.1"
-once_cell = { version = "1.20.2", default-features = false, features = [
+once_cell = { version = "1.21.1", default-features = false, features = [
   "critical-section",
 ] }
 hex = { version = "0.4.3", default-features = false }