diff --git a/src/parser/jsoncons/json_serializer.hpp b/src/parser/jsoncons/json_serializer.hpp
index f7f22adb..751775bc 100644
--- a/src/parser/jsoncons/json_serializer.hpp
+++ b/src/parser/jsoncons/json_serializer.hpp
@@ -50,7 +50,7 @@ class basic_json_serializer : public basic_json_output_handler<CharT>
 
         bool is_same_line() const
         {
-            return option_ = block_options::same_line;
+            return option_ == block_options::same_line;
         }
 
         bool is_next_line() const