diff --git a/include/spdlog/sinks/rotating_file_sink.h b/include/spdlog/sinks/rotating_file_sink.h
index 35c1e50a..4a016f44 100644
--- a/include/spdlog/sinks/rotating_file_sink.h
+++ b/include/spdlog/sinks/rotating_file_sink.h
@@ -7,6 +7,7 @@
 #include <spdlog/details/file_helper.h>
 #include <spdlog/details/null_mutex.h>
 #include <spdlog/details/synchronous_factory.h>
+#include <spdlog/details/os.h>
 
 #include <chrono>
 #include <mutex>