diff --git a/components/style/properties/longhand/inherited_table.mako.rs b/components/style/properties/longhand/inherited_table.mako.rs
index 1a6daa55417..b3cefca4304 100644
--- a/components/style/properties/longhand/inherited_table.mako.rs
+++ b/components/style/properties/longhand/inherited_table.mako.rs
@@ -114,15 +114,11 @@ ${helpers.single_keyword("caption-side", "top bottom",
             Err(()) => (),
             Ok(length) => {
                 first = Some(length);
-                match specified::Length::parse_non_negative(input) {
-                    Err(()) => (),
-                    Ok(length) => second = Some(length),
+                if let Ok(len) = input.try(|input| specified::Length::parse_non_negative(input)) {
+                    second = Some(len);
                 }
             }
         }
-        if input.next().is_ok() {
-            return Err(())
-        }
         match (first, second) {
             (None, None) => Err(()),
             (Some(length), None) => {
diff --git a/tests/unit/style/parsing/border.rs b/tests/unit/style/parsing/border.rs
index 56a0ad47a90..fe6ef2ef087 100644
--- a/tests/unit/style/parsing/border.rs
+++ b/tests/unit/style/parsing/border.rs
@@ -139,3 +139,12 @@ fn test_border_style() {
     assert_roundtrip_with_context!(BorderStyle::parse, r#"inset"#);
     assert_roundtrip_with_context!(BorderStyle::parse, r#"outset"#);
 }
+
+#[test]
+fn test_border_spacing() {
+    use style::properties::longhands::border_spacing;
+
+    assert_parser_exhausted!(border_spacing, "1px rubbish", false);
+    assert_parser_exhausted!(border_spacing, "1px", true);
+    assert_parser_exhausted!(border_spacing, "1px 2px", true);
+}
diff --git a/tests/unit/style/parsing/mod.rs b/tests/unit/style/parsing/mod.rs
index 627f995a6ff..72684bccc50 100644
--- a/tests/unit/style/parsing/mod.rs
+++ b/tests/unit/style/parsing/mod.rs
@@ -58,6 +58,17 @@ macro_rules! assert_roundtrip {
     }
 }
 
+macro_rules! assert_parser_exhausted {
+    ($name:ident, $string:expr, $should_exhausted:expr) => {{
+        let url = ::servo_url::ServoUrl::parse("http://localhost").unwrap();
+        let context = ParserContext::new(Origin::Author, &url, Box::new(CSSErrorReporterTest));
+        let mut parser = Parser::new($string);
+        let parsed = $name::parse(&context, &mut parser);
+        assert_eq!(parsed.is_ok(), true);
+        assert_eq!(parser.is_exhausted(), $should_exhausted);
+    }}
+}
+
 macro_rules! parse_longhand {
     ($name:ident, $s:expr) => {{
         let url = ::servo_url::ServoUrl::parse("http://localhost").unwrap();