diff --git a/Cargo.toml b/Cargo.toml
index 8fda8cde..44cec1ec 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,13 +11,13 @@ keywords = [ "selinux" ]
 
 [build-dependencies]
 lalrpop = "0.19"
-clap = { version = "3", features = ["derive"] }
-clap_mangen = "0.1"
+clap = { version = "4", features = ["derive"] }
+clap_mangen = "0.2"
 
 [dependencies]
 atty = "0.2"
 backtrace = "0.3"
-clap = { version = "3", features = ["derive"] }
+clap = { version = "4", features = ["derive"] }
 codespan-reporting = "0.11"
 lalrpop-util = "0.19"
 regex = "1"
diff --git a/src/bin/casc/args.rs b/src/bin/casc/args.rs
index 62160ccf..3e6264cf 100644
--- a/src/bin/casc/args.rs
+++ b/src/bin/casc/args.rs
@@ -20,7 +20,7 @@ pub struct Args {
     #[clap(default_value = "out.cil", short, value_parser = clap::builder::ValueParser::new(parse_out_filename))]
     pub out_filename: String,
     /// Build the systems from the SYSTEM_NAMES list. "-s all" to build all defined systems.
-    #[clap(short, conflicts_with = "out-filename")]
+    #[clap(short, conflicts_with = "out_filename")]
     pub system_names: Vec<String>,
     ///colorize the output.  WHEN can be 'always', 'auto' (default), or 'never'
     #[clap(long, value_enum, id = "WHEN")]
@@ -40,3 +40,14 @@ pub enum ColorArg {
     Auto,
     Never,
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use clap::CommandFactory;
+
+    #[test]
+    fn test_cli() {
+        Args::command().debug_assert();
+    }
+}