diff --git a/src/expr.rs b/src/expr.rs
index 2c562570265..0e84a9eb94a 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -630,8 +630,7 @@ fn rewrite_closure(
         }
 
         // Figure out if the block is necessary.
-        let needs_block = block.rules != ast::BlockCheckMode::Default || block.stmts.len() > 1
-            || context.inside_macro
+        let needs_block = is_unsafe_block(block) || block.stmts.len() > 1 || context.inside_macro
             || block_contains_comment(block, context.codemap)
             || prefix.contains('\n');