diff --git a/src/uu/csplit/src/csplit.rs b/src/uu/csplit/src/csplit.rs
index fe96f41534f..c4e9d9f5eed 100644
--- a/src/uu/csplit/src/csplit.rs
+++ b/src/uu/csplit/src/csplit.rs
@@ -680,6 +680,7 @@ pub fn uu_app() -> Command {
                 .short('b')
                 .long(options::SUFFIX_FORMAT)
                 .value_name("FORMAT")
+                .allow_hyphen_values(true)
                 .help(translate!("csplit-help-suffix-format")),
         )
         .arg(
diff --git a/tests/by-util/test_csplit.rs b/tests/by-util/test_csplit.rs
index ec60cfa2b9f..93985cc1bc4 100644
--- a/tests/by-util/test_csplit.rs
+++ b/tests/by-util/test_csplit.rs
@@ -1445,6 +1445,20 @@ fn precision_format() {
     }
 }
 
+#[test]
+fn suffix_format_hyphen_leading_as_separate_arg() {
+    // A hyphen-leading suffix format passed as its own argument (not
+    // attached with `-b-%02d`/`=`) must not be mistaken for a new,
+    // unrecognized flag.
+    let (at, mut ucmd) = at_and_ucmd!();
+    ucmd.args(&["numbers50.txt", "10", "--suffix-format", "-%02d"])
+        .succeeds()
+        .stdout_only("18\n123\n");
+
+    assert_eq!(at.read("xx-00"), generate(1, 10));
+    assert_eq!(at.read("xx-01"), generate(10, 51));
+}
+
 #[test]
 fn zero_precision_format() {
     let (at, mut ucmd) = at_and_ucmd!();