diff --git a/include/spdlog/async.h b/include/spdlog/async.h
index 250f4cdc..dbd9d073 100644
--- a/include/spdlog/async.h
+++ b/include/spdlog/async.h
@@ -26,7 +26,7 @@
 namespace spdlog {
 
 namespace details {
-static const size_t default_async_q_size = 8192;
+static constexpr size_t default_async_q_size = 8192;
 }
 
 // async logger factory - creates async loggers backed with thread pool.