diff --git a/src/tools/rustfmt/tests/source/mut_ref.rs b/src/tools/rustfmt/tests/source/mut_ref.rs
new file mode 100644
index 0000000000000..18ff33a99ce3f
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/mut_ref.rs
@@ -0,0 +1,10 @@
+#![feature(mut_ref)]
+fn mut_ref() {
+    if let Some(mut /*a*/ ref     /*def*/  mut     /*abc*/       state)=          /*abc*/foo{
+        println!(
+"asdfasdfasdf");	}
+
+if let Some(mut /*a*/ ref     /*def*/  /*mut*/       state)=          /*abc*/foo{
+    println!(
+"asdfasdfasdf");	}
+}
diff --git a/src/tools/rustfmt/tests/target/mut_ref.rs b/src/tools/rustfmt/tests/target/mut_ref.rs
new file mode 100644
index 0000000000000..1603524379115
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/mut_ref.rs
@@ -0,0 +1,10 @@
+#![feature(mut_ref)]
+fn mut_ref() {
+    if let Some(mut /*a*/ ref /*def*/ mut /*abc*/ state) = /*abc*/ foo {
+        println!("asdfasdfasdf");
+    }
+
+    if let Some(mut /*a*/ ref /*def*/  /*mut*/ state) = /*abc*/ foo {
+        println!("asdfasdfasdf");
+    }
+}