diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 746f416..947c47d 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -96,7 +96,13 @@ extern int cacheflush(char *addr, int nbytes, int cache);
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
+
+#ifdef _MSC_VER
+#include <io.h>
+typedef SSIZE_T	ssize_t;
+#else
 #include <unistd.h>
+#endif
 
 #if defined(__sun) || defined(ANDROID)
 /* Most platforms have posix_memalign, older may only have memalign */