diff --git a/Cargo.lock b/Cargo.lock
index 8d1d872..b48f033 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -34,9 +34,9 @@ dependencies = [
 
 [[package]]
 name = "async-trait"
-version = "0.1.73"
+version = "0.1.77"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc00ceb34980c03614e35a3a4e218276a0a824e911d07651cd0d858a51e8c0f0"
+checksum = "c980ee35e870bd1a4d2c8294d4c04d0499e67bca1e4b5cefcc693c2fa00caea9"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -72,9 +72,9 @@ checksum = "ed570934406eb16438a4e976b1b4500774099c13b8cb96eec99f620f05090ddf"
 
 [[package]]
 name = "bumpalo"
-version = "3.13.0"
+version = "3.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a3e2c3daef883ecc1b5d58c15adae93470a91d425f3532ba1695849656af3fc1"
+checksum = "7f30e7476521f6f8af1a1c4c0b8cc94f0bee37d91763d0ca2665f299b6cd8aec"
 
 [[package]]
 name = "byte-strings"
@@ -133,21 +133,21 @@ dependencies = [
 
 [[package]]
 name = "core-foundation-sys"
-version = "0.8.4"
+version = "0.8.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e496a50fda8aacccc86d7529e2c1e0892dbd0f898a6b5645b5561b89c3210efa"
+checksum = "06ea2b9bc92be3c2baa9334a323ebca2d6f074ff852cd1d7b11064035cd3868f"
 
 [[package]]
 name = "futures-core"
-version = "0.3.28"
+version = "0.3.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4bca583b7e26f571124fe5b7561d49cb2868d79116cfa0eefce955557c6fee8c"
+checksum = "dfc6580bb841c5a68e9ef15c77ccc837b40a7504914d52e47b8b0e9bbda25a1d"
 
 [[package]]
 name = "futures-macro"
-version = "0.3.28"
+version = "0.3.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89ca545a94061b6365f2c7355b4b32bd20df3ff95f02da9329b34ccc3bd6ee72"
+checksum = "87750cf4b7a4c0625b1529e4c543c2182106e4dedc60a2a6455e00d212c489ac"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -156,15 +156,15 @@ dependencies = [
 
 [[package]]
 name = "futures-task"
-version = "0.3.28"
+version = "0.3.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "76d3d132be6c0e6aa1534069c705a74a5997a356c0dc2f86a47765e5617c5b65"
+checksum = "38d84fa142264698cdce1a9f9172cf383a0c82de1bddcf3092901442c4097004"
 
 [[package]]
 name = "futures-util"
-version = "0.3.28"
+version = "0.3.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26b01e40b772d54cf6c6d721c1d1abd0647a0106a12ecaa1c186273392a69533"
+checksum = "3d6401deb83407ab3da39eba7e33987a73c3df0c82b4bb5813ee871c19c41d48"
 dependencies = [
  "futures-core",
  "futures-macro",
@@ -176,9 +176,9 @@ dependencies = [
 
 [[package]]
 name = "getrandom"
-version = "0.2.10"
+version = "0.2.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "be4136b2a15dd319360be1c07d9933517ccf0be8f16bf62a3bee4f0d618df427"
+checksum = "190092ea657667030ac6a35e305e62fc4dd69fd98ac98631e5d3a2b1575a12b5"
 dependencies = [
  "cfg-if",
  "libc",
@@ -187,15 +187,15 @@ dependencies = [
 
 [[package]]
 name = "gimli"
-version = "0.28.0"
+version = "0.28.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6fb8d784f27acf97159b40fc4db5ecd8aa23b9ad5ef69cdd136d3bc80665f0c0"
+checksum = "4271d37baee1b8c7e4b708028c57d816cf9d2434acb33a549475f78c181f6253"
 
 [[package]]
 name = "hermit-abi"
-version = "0.3.2"
+version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "443144c8cdadd93ebf52ddb4056d257f5b52c04d3c804e657d19eb73fc33668b"
+checksum = "d77f7ec81a6d05a3abb01ab6eb7590f6083d08449fe5a1c8b1e620283546ccb7"
 
 [[package]]
 name = "iana-time-zone"
@@ -246,24 +246,24 @@ dependencies = [
 
 [[package]]
 name = "ipnet"
-version = "2.8.0"
+version = "2.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28b29a3cd74f0f4598934efe3aeba42bae0eb4680554128851ebbecb02af14e6"
+checksum = "8f518f335dce6725a761382244631d86cf0ccb2863413590b31338feb467f9c3"
 
 [[package]]
 name = "js-sys"
-version = "0.3.64"
+version = "0.3.67"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c5f195fe497f702db0f318b07fdd68edb16955aed830df8363d837542f8f935a"
+checksum = "9a1d36f1235bc969acba30b7f5990b864423a6068a10f7c90ae8f0112e3a59d1"
 dependencies = [
  "wasm-bindgen",
 ]
 
 [[package]]
 name = "libc"
-version = "0.2.147"
+version = "0.2.152"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b4668fb0ea861c1df094127ac5f1da3409a82116a4ba74fca2e58ef927159bb3"
+checksum = "13e3bf6590cbc649f4d1a3eefc9d5d6eb746f5200ffb04e5e142700b8faa56e7"
 
 [[package]]
 name = "log"
@@ -273,9 +273,9 @@ checksum = "b5e6163cb8c49088c2c36f57875e58ccd8c87c7427f7fbd50ea6710b2f3f2e8f"
 
 [[package]]
 name = "memchr"
-version = "2.6.3"
+version = "2.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f232d6ef707e1956a43342693d2a31e72989554d58299d7a88738cc95b0d35c"
+checksum = "523dc4f511e55ab87b694dc30d0f820d60906ef06413f93d4d7a1385599cc149"
 
 [[package]]
 name = "miniz_oxide"
@@ -288,9 +288,9 @@ dependencies = [
 
 [[package]]
 name = "mio"
-version = "0.8.8"
+version = "0.8.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "927a765cd3fc26206e66b296465fa9d3e5ab003e651c1b3c060e7956d96b19d2"
+checksum = "8f3d0b296e374a4e6f3c7b0a1f5a51d748a0d34c85e7dc48fc3fa9a87657fe09"
 dependencies = [
  "libc",
  "wasi",
@@ -299,9 +299,9 @@ dependencies = [
 
 [[package]]
 name = "num-traits"
-version = "0.2.16"
+version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f30b0abd723be7e2ffca1272140fac1a2f084c77ec3e123c192b66af1ee9e6c2"
+checksum = "39e3200413f237f41ab11ad6d161bc7239c84dcb631773ccd7de3dfe4b5c267c"
 dependencies = [
  "autocfg",
 ]
@@ -318,18 +318,18 @@ dependencies = [
 
 [[package]]
 name = "object"
-version = "0.32.1"
+version = "0.32.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9cf5f9dd3933bd50a9e1f149ec995f39ae2c496d31fd772c1fd45ebc27e902b0"
+checksum = "a6a622008b6e321afc04970976f62ee297fdbaa6f95318ca343e3eebb9648441"
 dependencies = [
  "memchr",
 ]
 
 [[package]]
 name = "once_cell"
-version = "1.18.0"
+version = "1.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd8b5dd2ae5ed71462c540258bedcb51965123ad7e7ccf4b9a8cafaa4a63576d"
+checksum = "3fdb12b2476b595f9358c5161aa467c2438859caa136dec86c26fdd2efe17b92"
 
 [[package]]
 name = "pin-project-lite"
@@ -351,18 +351,18 @@ checksum = "5b40af805b3121feab8a3c29f04d8ad262fa8e0561883e7653e024ae4479e6de"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.66"
+version = "1.0.78"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18fb31db3f9bddb2ea821cde30a9f70117e3f119938b5ee630b7403aa6e2ead9"
+checksum = "e2422ad645d89c99f8f3e6b88a9fdeca7fabeac836b1002371c4367c8f984aae"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.33"
+version = "1.0.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
+checksum = "291ec9ab5efd934aaf503a6466c5d5251535d108ee747472c3977cc5acc868ef"
 dependencies = [
  "proc-macro2",
 ]
@@ -445,9 +445,9 @@ dependencies = [
 
 [[package]]
 name = "socket2"
-version = "0.5.3"
+version = "0.5.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2538b18701741680e0322a2302176d3253a35388e2e62f172f64f4f16605f877"
+checksum = "7b5fac59a5cb5dd637972e5fca70daf0523c9067fcdc4842f053dae04a18f8e9"
 dependencies = [
  "libc",
  "windows-sys",
@@ -473,9 +473,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.31"
+version = "2.0.48"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "718fa2415bcb8d8bd775917a1bf12a7931b6dfa890753378538118181e0cb398"
+checksum = "0f3531638e407dfc0814761abb7c00a5b54992b849452a0646b7f65c9f770f3f"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -484,9 +484,9 @@ dependencies = [
 
 [[package]]
 name = "tokio"
-version = "1.32.0"
+version = "1.36.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "17ed6077ed6cd6c74735e21f37eb16dc3935f96878b1fe961074089cc80893f9"
+checksum = "61285f6515fa018fb2d1e46eb21223fff441ee8db5d0f1435e8ab4f5cdb80931"
 dependencies = [
  "backtrace",
  "bytes",
@@ -502,9 +502,9 @@ dependencies = [
 
 [[package]]
 name = "tokio-macros"
-version = "2.1.0"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "630bdcf245f78637c13ec01ffae6187cca34625e8c63150d424b59e55af2675e"
+checksum = "5b8a1e28f2deaa14e508979454cb3a223b10b938b45af148bc0986de36f1923b"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -532,9 +532,9 @@ dependencies = [
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.11"
+version = "1.0.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "301abaae475aa91687eb82514b328ab47a211a533026cb25fc3e519b86adfc3c"
+checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"
 
 [[package]]
 name = "wasi"
@@ -544,9 +544,9 @@ checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.87"
+version = "0.2.90"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7706a72ab36d8cb1f80ffbf0e071533974a60d0a308d01a5d0375bf60499a342"
+checksum = "b1223296a201415c7fad14792dbefaace9bd52b62d33453ade1c5b5f07555406"
 dependencies = [
  "cfg-if",
  "wasm-bindgen-macro",
@@ -554,9 +554,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.87"
+version = "0.2.90"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ef2b6d3c510e9625e5fe6f509ab07d66a760f0885d858736483c32ed7809abd"
+checksum = "fcdc935b63408d58a32f8cc9738a0bffd8f05cc7c002086c6ef20b7312ad9dcd"
 dependencies = [
  "bumpalo",
  "log",
@@ -569,9 +569,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.87"
+version = "0.2.90"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dee495e55982a3bd48105a7b947fd2a9b4a8ae3010041b9e0faab3f9cd028f1d"
+checksum = "3e4c238561b2d428924c49815533a8b9121c664599558a5d9ec51f8a1740a999"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -579,9 +579,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.87"
+version = "0.2.90"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "54681b18a46765f095758388f2d0cf16eb8d4169b639ab575a8f5693af210c7b"
+checksum = "bae1abb6806dc1ad9e560ed242107c0f6c84335f1749dd4e8ddb012ebd5e25a7"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -592,9 +592,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.87"
+version = "0.2.90"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ca6ad05a4870b2bf5fe995117d3728437bd27d7cd5f06f13c17443ef369775a1"
+checksum = "4d91413b1c31d7539ba5ef2451af3f0b833a005eb27a631cec32bc0635a8602b"
 
 [[package]]
 name = "windows"
diff --git a/Cargo.toml b/Cargo.toml
index 96f86b6..8d1a8e2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,18 +11,18 @@ repository = "https://gitlab.com/glts/spamassassin-milter"
 exclude = ["/.gitignore", "/.gitlab-ci.yml"]
 
 [dependencies]
-async-trait = "0.1.73"
+async-trait = "0.1.77"
 byte-strings = "0.3.1"
 chrono = "0.4.31"
-futures-util = "0.3.28"
+futures-util = "0.3.30"
 indymilter = "0.3.0-alpha.2"
-ipnet = "2.8.0"
-once_cell = "1.18.0"
+ipnet = "2.9.0"
+once_cell = "1.19.0"
 signal-hook = "0.3.17"
 signal-hook-tokio = { version = "0.3.1", features = ["futures-v0_3"] }
-tokio = { version = "1.32.0", features = ["fs", "io-util", "macros", "net", "process", "rt", "rt-multi-thread", "sync"] }
+tokio = { version = "1.36.0", features = ["fs", "io-util", "macros", "net", "process", "rt", "rt-multi-thread", "sync"] }
 
 [dev-dependencies]
 indymilter-test = "0.2.0-alpha.1"
 rand = "0.8.5"
-tokio = { version = "1.32.0", features = ["signal", "time"] }
+tokio = { version = "1.36.0", features = ["signal", "time"] }
diff --git a/src/main.rs b/src/main.rs
index a68d05c..bc5c768 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -287,11 +287,10 @@ fn spawn_signals_task(
     shutdown_milter: oneshot::Sender<()>,
 ) -> JoinHandle<()> {
     tokio::spawn(async move {
-        while let Some(signal) = signals.next().await {
+        if let Some(signal) = signals.next().await {
             match signal {
                 SIGINT | SIGTERM => {
                     let _ = shutdown_milter.send(());
-                    break;
                 }
                 _ => panic!("unexpected signal"),
             }