diff --git a/src/expr.rs b/src/expr.rs
index 332d1f5a2f3..2bcb1d6d727 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -1134,11 +1134,10 @@ fn rewrite_unary_op(context: &RewriteContext,
         ast::UnOp::UnNot => "!",
         ast::UnOp::UnNeg => "-",
     };
+    let operator_len = operator_str.len();
 
-    let subexpr =
-        try_opt!(expr.rewrite(context, try_opt!(width.checked_sub(operator_str.len())), offset));
-
-    Some(format!("{}{}", operator_str, subexpr))
+    expr.rewrite(context, try_opt!(width.checked_sub(operator_len)), offset + operator_len)
+        .map(|r| format!("{}{}", operator_str, r))
 }
 
 fn rewrite_assignment(context: &RewriteContext,
diff --git a/tests/source/expr.rs b/tests/source/expr.rs
index 85ee7727451..d5e98f959d1 100644
--- a/tests/source/expr.rs
+++ b/tests/source/expr.rs
@@ -105,3 +105,9 @@ fn qux() {
         // A block with a comment.
     }
 }
+
+fn issue227() {
+    {
+        let handler = box DocumentProgressHandler::new(addr, DocumentProgressTask::DOMContentLoaded);
+    }
+}
diff --git a/tests/target/expr.rs b/tests/target/expr.rs
index 45c654b738f..afc152ac828 100644
--- a/tests/target/expr.rs
+++ b/tests/target/expr.rs
@@ -139,3 +139,10 @@ fn qux() {
         // A block with a comment.
     }
 }
+
+fn issue227() {
+    {
+        let handler = box DocumentProgressHandler::new(addr,
+                                                       DocumentProgressTask::DOMContentLoaded);
+    }
+}