diff --git a/src/uu/seq/src/numberparse.rs b/src/uu/seq/src/numberparse.rs
index 79e7068e3..891fa2ce6 100644
--- a/src/uu/seq/src/numberparse.rs
+++ b/src/uu/seq/src/numberparse.rs
@@ -392,6 +392,7 @@ mod tests {
     fn test_parse_big_int() {
         assert_eq!(parse("0"), ExtendedBigDecimal::zero());
         assert_eq!(parse("0.1e1"), ExtendedBigDecimal::one());
+        assert_eq!(parse("0.1E1"), ExtendedBigDecimal::one());
         assert_eq!(
             parse("1.0e1"),
             ExtendedBigDecimal::BigDecimal("10".parse::<BigDecimal>().unwrap())
diff --git a/tests/by-util/test_seq.rs b/tests/by-util/test_seq.rs
index c14d30629..ab0659f21 100644
--- a/tests/by-util/test_seq.rs
+++ b/tests/by-util/test_seq.rs
@@ -333,6 +333,11 @@ fn test_width_scientific_notation() {
         .succeeds()
         .stdout_is("0999\n1000\n")
         .no_stderr();
+    new_ucmd!()
+        .args(&["-w", "999", "1E3"])
+        .succeeds()
+        .stdout_is("0999\n1000\n")
+        .no_stderr();
 }
 
 #[test]