diff --git a/Cargo.lock b/Cargo.lock
index 48f68ebd..16d03fe2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -122,6 +122,12 @@ version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ec8a7b6a70fde80372154c65702f00a0f56f3e1c36abbc6c440484be248856db"
 
+[[package]]
+name = "cc"
+version = "1.0.73"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2fff2a6927b3bb87f9595d67196a70493f627687a71d87a0d692242c33f58c11"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -138,6 +144,7 @@ dependencies = [
  "clap_derive",
  "clap_lex",
  "once_cell",
+ "terminal_size",
 ]
 
 [[package]]
@@ -300,6 +307,27 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "errno"
+version = "0.2.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f639046355ee4f37944e44f60642c6f3a7efa3cf6b78c78a0d989a8ce6c396a1"
+dependencies = [
+ "errno-dragonfly",
+ "libc",
+ "winapi",
+]
+
+[[package]]
+name = "errno-dragonfly"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa68f1b12764fab894d2755d2518754e71b4fd80ecfb822714a1206c2aab39bf"
+dependencies = [
+ "cc",
+ "libc",
+]
+
 [[package]]
 name = "ff"
 version = "0.12.0"
@@ -498,6 +526,12 @@ dependencies = [
  "want",
 ]
 
+[[package]]
+name = "io-lifetimes"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ea37f355c05dde75b84bba2d767906ad522e97cd9e2eef2be7a4ab7fb442c06"
+
 [[package]]
 name = "itoa"
 version = "1.0.3"
@@ -525,6 +559,12 @@ version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "292a948cd991e376cf75541fe5b97a1081d713c618b4f1b9500f8844e49eb565"
 
+[[package]]
+name = "linux-raw-sys"
+version = "0.0.46"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d4d2456c373231a208ad294c33dc5bff30051eafd954cd4caae83a712b12854d"
+
 [[package]]
 name = "log"
 version = "0.4.17"
@@ -919,6 +959,20 @@ dependencies = [
  "semver",
 ]
 
+[[package]]
+name = "rustix"
+version = "0.35.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fbb2fda4666def1433b1b05431ab402e42a1084285477222b72d6c564c417cef"
+dependencies = [
+ "bitflags",
+ "errno",
+ "io-lifetimes",
+ "libc",
+ "linux-raw-sys",
+ "windows-sys",
+]
+
 [[package]]
 name = "rustls-pemfile"
 version = "0.3.0"
@@ -1122,6 +1176,16 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "20518fe4a4c9acf048008599e464deb21beeae3d3578418951a189c235a7a9a8"
 
+[[package]]
+name = "terminal_size"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8440c860cf79def6164e4a0a983bcc2305d82419177a0e0c71930d049e3ac5a1"
+dependencies = [
+ "rustix",
+ "windows-sys",
+]
+
 [[package]]
 name = "testaso"
 version = "0.1.0"
diff --git a/Cargo.toml b/Cargo.toml
index 04c05c26..88f38acc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -29,7 +29,7 @@ rand = { version = "0.8", features = ["std"], default-features = false }
 tracing-subscriber = { version="^0.3.15", features = ["env-filter", "json", "fmt"], default-features = false }
 tower-http = { version = "^0.3.0", features = ["trace"], default-features = false }
 axum = { version = "^0.5.16", features = ["headers"], default-features = false }
-clap = { version = "^4.0.17", features = ["std", "derive", "env"], default-features = false }
+clap = { version = "^4.0.17", features = ["help", "usage", "error-context", "std", "derive", "env"], default-features = false }
 hyper = { git = "https://github.com/rjzak/hyper", branch = "wasi_wip", features = ["http1", "server"], default-features = false }
 tokio = { version = "^1.21.2", features = ["rt", "macros"], default-features = false }
 uuid = { version = "^0.8.2", features = ["v4"], default-features = false }
diff --git a/src/main.rs b/src/main.rs
index a4551224..63e013b8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -66,24 +66,24 @@ const BUNDLE: &str = "application/vnd.steward.pkcs10-bundle.v1";
 /// The configuration file must contain valid TOML table mapping argument
 /// names to their values.
 #[derive(Clone, Debug, Parser)]
-#[clap(author, version, about)]
+#[command(author, version, about)]
 struct Args {
-    #[clap(short, long, env = "STEWARD_KEY")]
+    #[arg(short, long, env = "STEWARD_KEY")]
     key: Option<PathBuf>,
 
-    #[clap(short, long, env = "STEWARD_CRT")]
+    #[arg(short, long, env = "STEWARD_CRT")]
     crt: Option<PathBuf>,
 
-    #[clap(short, long, env = "ROCKET_PORT", default_value = "3000")]
+    #[arg(short, long, env = "ROCKET_PORT", default_value = "3000")]
     port: u16,
 
-    #[clap(short, long, env = "ROCKET_ADDRESS", default_value = "::")]
+    #[arg(short, long, env = "ROCKET_ADDRESS", default_value = "::")]
     addr: IpAddr,
 
-    #[clap(short, long, env = "RENDER_EXTERNAL_HOSTNAME")]
+    #[arg(long, env = "RENDER_EXTERNAL_HOSTNAME")]
     host: Option<String>,
 
-    #[clap(long, env = "STEWARD_SAN")]
+    #[arg(long, env = "STEWARD_SAN")]
     san: Option<String>,
 }