diff --git a/util/mutex.h b/util/mutex.h
index e2a8715..e1587d5 100644
--- a/util/mutex.h
+++ b/util/mutex.h
@@ -12,6 +12,7 @@
 
 #ifdef _WIN32
 // Requires Windows Vista or Windows Server 2008 at minimum.
+#include <windows.h>
 #if defined(WINVER) && WINVER >= 0x0600
 #define MUTEX_IS_WIN32_SRWLOCK
 #endif
@@ -26,7 +27,6 @@
 #endif
 
 #if defined(MUTEX_IS_WIN32_SRWLOCK)
-#include <windows.h>
 typedef SRWLOCK MutexType;
 #elif defined(MUTEX_IS_PTHREAD_RWLOCK)
 #include <pthread.h>