diff --git a/src/pattern_formatter.cpp b/src/pattern_formatter.cpp
index 04723fb9..0456121e 100644
--- a/src/pattern_formatter.cpp
+++ b/src/pattern_formatter.cpp
@@ -65,9 +65,7 @@ public:
     }
 
 private:
-    void pad_it(long count) {
-        dest_.append(spaces_.data(), spaces_.data() + static_cast<size_t>(count));
-    }
+    void pad_it(long count) { fmt_helper::append_string_view(string_view_t(spaces_.data(), static_cast<size_t>(count)), dest_); }
 
     const padding_info &padinfo_;
     memory_buf_t &dest_;