diff --git a/src/bin/hexyl.rs b/src/bin/hexyl.rs
index 1417c17..367cc4e 100644
--- a/src/bin/hexyl.rs
+++ b/src/bin/hexyl.rs
@@ -61,6 +61,7 @@ fn run() -> Result<(), AnyhowError> {
                 .short("l")
                 .takes_value(true)
                 .value_name("N")
+                .conflicts_with_all(&["length", "bytes"])
                 .hidden(true)
                 .help("Yet another alias for -n/--length"),
         )
diff --git a/tests/integration_tests.rs b/tests/integration_tests.rs
index 0508e53..bc718ad 100644
--- a/tests/integration_tests.rs
+++ b/tests/integration_tests.rs
@@ -85,6 +85,30 @@ mod length {
             .assert()
             .failure();
     }
+
+    #[test]
+    fn fail_if_length_and_count_options_are_used_simultaneously() {
+        hexyl()
+            .arg("hello_world_elf64")
+            .arg("--length=32")
+            .arg("-l=10")
+            .assert()
+            .failure();
+    }
+}
+
+mod bytes {
+    use super::hexyl;
+
+    #[test]
+    fn fail_if_bytes_and_count_options_are_used_simultaneously() {
+        hexyl()
+            .arg("hello_world_elf64")
+            .arg("--bytes=32")
+            .arg("-l=10")
+            .assert()
+            .failure();
+    }
 }
 
 mod skip {