diff --git a/include/spdlog/details/circular_q.h b/include/spdlog/details/circular_q.h
index d07f0725..f06cd8e5 100644
--- a/include/spdlog/details/circular_q.h
+++ b/include/spdlog/details/circular_q.h
@@ -77,11 +77,11 @@ public:
     {
         if (tail_ > head_)
         {
-           return (tail_ - head_) % max_items;
+           return (tail_ - head_) % max_items_;
         }
         else
         {
-            return max_items - (head_ - tail_ ) % max_items;
+            return max_items_ - (head_ - tail_ ) % max_items_;
         }
     }