diff --git a/src/utils.rs b/src/utils.rs
index 6a19525..5cab9ef 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -359,10 +359,19 @@ fn ident_body<I: Iterator<Item = Token>>(
         span = span.merge(tok.pos());
         if unit && tok.kind == '-' {
             // Disallow `-` followed by a dot or a digit digit in units.
+            let second = match toks.peek_forward(1) {
+                Some(v) => v.clone(),
+                None => break,
+            };
+
+            toks.peek_backward(1).unwrap();
+
+            if second.kind == '.' || second.kind.is_ascii_digit() {
+                break;
+            }
             toks.next();
-        // var second = scanner.peekChar(1);
-        // if (second != null && (second == $dot || isDigit(second))) break;
-        // text.writeCharCode(scanner.readChar());
+            text.push('-');
+            text.push(toks.next().unwrap().kind);
         } else if is_name(tok.kind) {
             text.push(toks.next().unwrap().kind);
         } else if tok.kind == '\\' {
diff --git a/tests/units.rs b/tests/units.rs
index 4546781..3b7f339 100644
--- a/tests/units.rs
+++ b/tests/units.rs
@@ -69,6 +69,11 @@ test!(
     "a {\n  color: 10% + 10;\n}\n",
     "a {\n  color: 20%;\n}\n"
 );
+test!(
+    unit_no_hyphen,
+    "a {\n  color: 1px-2px;\n}\n",
+    "a {\n  color: -1px;\n}\n"
+);
 error!(
     display_single_mul,
     "a {\n  color: 1rem * 1px;\n}\n", "Error: 1rem*px isn't a valid CSS value."