diff --git a/src/uu/hashsum/src/hashsum.rs b/src/uu/hashsum/src/hashsum.rs
index 708596096..39b5a0a07 100644
--- a/src/uu/hashsum/src/hashsum.rs
+++ b/src/uu/hashsum/src/hashsum.rs
@@ -481,7 +481,8 @@ fn uu_app_opt_length(command: Command) -> Command {
             .long("length")
             .help("digest length in bits; must not exceed the max for the blake2 algorithm (512) and must be a multiple of 8")
             .value_name("BITS")
-            .value_parser(parse_bit_num),
+            .value_parser(parse_bit_num)
+            .overrides_with("length"),
     )
 }
 
diff --git a/tests/by-util/test_hashsum.rs b/tests/by-util/test_hashsum.rs
index a3a5849ff..eed265ac5 100644
--- a/tests/by-util/test_hashsum.rs
+++ b/tests/by-util/test_hashsum.rs
@@ -180,6 +180,22 @@ fn test_check_b2sum_length_option_0() {
         .stdout_only("testf: OK\n");
 }
 
+#[test]
+fn test_check_b2sum_length_duplicate() {
+    let scene = TestScenario::new(util_name!());
+    let at = &scene.fixtures;
+
+    at.write("testf", "foobar\n");
+
+    scene
+        .ccmd("b2sum")
+        .arg("--length=123")
+        .arg("--length=128")
+        .arg("testf")
+        .succeeds()
+        .stdout_contains("d6d45901dec53e65d2b55fb6e2ab67b0");
+}
+
 #[test]
 fn test_check_b2sum_length_option_8() {
     let scene = TestScenario::new(util_name!());