diff --git a/src/platforms/windows/windowsHandler.cpp b/src/platforms/windows/windowsHandler.cpp
index 9a3a85e3..6d1f4144 100644
--- a/src/platforms/windows/windowsHandler.cpp
+++ b/src/platforms/windows/windowsHandler.cpp
@@ -36,6 +36,7 @@
 #include <process.h>
 #include <windows.h>  // for winnls.h
 #include <winsock2.h> // for WSAStartup()
+#include <wincrypt.h>
 
 #ifdef VMIME_HAVE_MLANG_H
 #   include <mlang.h>