diff --git a/library/x509_crt.c b/library/x509_crt.c
index a6fcd1b4e6..29050aa12b 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -67,6 +67,11 @@
 #include <dirent.h>
 #endif /* __MBED__ */
 #include <errno.h>
+#else
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#endif
+#include <windows.h>
 #endif /* !_WIN32 || EFIX64 || EFI32 */
 #endif