diff --git a/src/uu/unexpand/src/unexpand.rs b/src/uu/unexpand/src/unexpand.rs
index d45da4ba46..0d26088bc0 100644
--- a/src/uu/unexpand/src/unexpand.rs
+++ b/src/uu/unexpand/src/unexpand.rs
@@ -48,7 +48,8 @@ fn parse_tab_num(word: &str, allow_zero: bool) -> Result<usize, ParseError> {
 }
 
 fn parse_tabstops(s: &str) -> Result<TabConfig, ParseError> {
-    let words = s.split(',');
+    // GNU accepts a blank (space or tab) or a comma as tab-list separators.
+    let words = s.split([' ', '\t', ',']);
 
     let mut nums = Vec::new();
     let mut increment_size: Option<usize> = None;
diff --git a/tests/by-util/test_unexpand.rs b/tests/by-util/test_unexpand.rs
index be30d46d0d..ae9d86aae1 100644
--- a/tests/by-util/test_unexpand.rs
+++ b/tests/by-util/test_unexpand.rs
@@ -270,6 +270,18 @@ fn test_comma_separated_tabs_shortcut() {
         .stdout_is("a\tb\tc");
 }
 
+#[test]
+fn test_blank_separated_tabs() {
+    // GNU accepts a space or a tab as a tab-list separator, just like a comma.
+    for sep in [" ", "\t"] {
+        new_ucmd!()
+            .args(&["-a", "-t", &format!("3{sep}9")])
+            .pipe_in("a  b     c")
+            .succeeds()
+            .stdout_is("a\tb\tc");
+    }
+}
+
 #[test]
 fn test_tabs_cannot_be_zero() {
     new_ucmd!()