diff --git a/sc2/src/sc2code/libs/uio/zip/zip.h b/sc2/src/sc2code/libs/uio/zip/zip.h
index 0c02f385e..e2603d5ac 100644
--- a/sc2/src/sc2code/libs/uio/zip/zip.h
+++ b/sc2/src/sc2code/libs/uio/zip/zip.h
@@ -33,6 +33,19 @@ typedef struct uio_GPDirEntries_Iterator *uio_NativeEntriesContext;
 #include "../types.h"
 #include "../fileblock.h"
 
+#ifdef _MSC_VER
+// these are needed to avoid zlib linking problems in VC
+#ifndef ZLIB_WINAPI
+#define ZLIB_WINAPI
+#endif
+#ifndef ZLIB_DLL
+#define ZLIB_DLL
+#endif
+#ifndef _WINDOWS
+#define _WINDOWS
+#endif
+#endif
+
 #include <zlib.h>
 #include <sys/types.h>
 #include <sys/stat.h>