diff --git a/test/css/parens.css b/test/css/parens.css
index 412823fb..dc09fdf5 100644
--- a/test/css/parens.css
+++ b/test/css/parens.css
@@ -31,3 +31,6 @@
   margin: 2px 4em 1 5pc;
   padding: 6px 1em 2px 2;
 }
+.test-false-negatives {
+  a: (;
+}
diff --git a/test/less/parens.less b/test/less/parens.less
index deb41391..eeef3448 100644
--- a/test/less/parens.less
+++ b/test/less/parens.less
@@ -39,3 +39,7 @@
   margin: 2px 4em 1 5pc;
   padding: (2px + 4px) 1em 2px 2;
 }
+
+.test-false-negatives {
+  a: ~"(";
+}