diff --git a/src/details/os_windows.cpp b/src/details/os_windows.cpp
index e64e9082..6cbf94f3 100644
--- a/src/details/os_windows.cpp
+++ b/src/details/os_windows.cpp
@@ -23,6 +23,7 @@
 #include <ctime>
 #include <string>
 #include <thread>
+#include <cassert>
 
 #include "spdlog/common.h"
 #include "spdlog/details/os.h"