diff --git a/lib/less/to-css-visitor.js b/lib/less/to-css-visitor.js
index 5668aca1b..af4ac5432 100644
--- a/lib/less/to-css-visitor.js
+++ b/lib/less/to-css-visitor.js
@@ -189,12 +189,12 @@
                         rule.important ? "!" : ""].join(",");
 
                     if (!groups[key]) {
-                        parts = groups[key] = [];
+                        groups[key] = [];
                     } else {
                         rules.splice(i--, 1);
                     }
 
-                    parts.push(rule);
+                    groups[key].push(rule);
                 }
             }
 
diff --git a/test/css/merge.css b/test/css/merge.css
index 4cf8c579e..18539f1a8 100644
--- a/test/css/merge.css
+++ b/test/css/merge.css
@@ -20,3 +20,7 @@
 .test6 {
   transform: scale(2, 4);
 }
+.test-interleaved {
+  transform: t1, t2, t3;
+  background: b1, b2, b3;
+}
diff --git a/test/less/merge.less b/test/less/merge.less
index 52d0796e3..f7070d631 100644
--- a/test/less/merge.less
+++ b/test/less/merge.less
@@ -36,7 +36,7 @@
   .first-background();
 }
 .test4 {
-  // Wont merge values from sources that merked as !important, for backwards compatibility with css 
+  // Wont merge values from sources that merked as !important, for backwards compatibility with css
   .first-transform();
   .fifth-transform();
 }
@@ -48,4 +48,12 @@
 .test6 {
   // Ignores !merge if no peers found
   .second-transform();
+}
+
+.test-interleaved {
+    transform+:  t1;
+    background+: b1;
+    transform+:  t2;
+    background+: b2, b3;
+    transform+:  t3;
 }
\ No newline at end of file