diff --git a/include/spdlog/details/circular_q.h b/include/spdlog/details/circular_q.h
index e4fd5fd4..d40e1418 100644
--- a/include/spdlog/details/circular_q.h
+++ b/include/spdlog/details/circular_q.h
@@ -82,7 +82,7 @@ public:
         }
         else
         {
-            return max_items_ - (head_ - tail_);
+            return max_items_ - 1 - (head_ - tail_);
         }
     }