diff --git a/compat/ioapi.h b/compat/ioapi.h
index 79cffc8..9359259 100644
--- a/compat/ioapi.h
+++ b/compat/ioapi.h
@@ -5,7 +5,14 @@
 #include <stdint.h>
 
 #ifndef _ZLIB_H
-//#include "zlib.h"
+#  include "zlib.h"
+#endif
+
+#ifndef Z_ERRNO
+#define Z_ERRNO                         (-1)
+#endif
+#ifndef Z_DEFLATED
+#define Z_DEFLATED                      (8)
 #endif
 
 typedef uint64_t ZPOS64_T;
diff --git a/compat/unzip.h b/compat/unzip.h
index 7c24b60..0c08154 100644
--- a/compat/unzip.h
+++ b/compat/unzip.h
@@ -38,18 +38,6 @@ typedef void *unzFile;
 
 /***************************************************************************/
 
-#ifndef Z_ERRNO
-#define Z_ERRNO                         (-1)
-#endif
-#ifndef Z_DEFLATED
-#define Z_DEFLATED                      (8)
-#endif
-#ifndef Z_BZIP2ED
-#define Z_BZIP2ED                       (12)
-#endif
-
-/***************************************************************************/
-
 #define UNZ_OK                  (0)
 #define UNZ_END_OF_LIST_OF_FILE (-100)
 #define UNZ_ERRNO               (Z_ERRNO)
diff --git a/compat/zip.h b/compat/zip.h
index 5c1f125..67f5a5b 100644
--- a/compat/zip.h
+++ b/compat/zip.h
@@ -38,16 +38,6 @@ typedef void *zipFile;
 
 /***************************************************************************/
 
-#ifndef Z_ERRNO
-#define Z_ERRNO                         (-1)
-#endif
-#ifndef Z_DEFLATED
-#define Z_DEFLATED                      (8)
-#endif
-#ifndef Z_BZIP2ED
-#define Z_BZIP2ED                       (12)
-#endif
-
 #define ZIP_OK            (0)
 #define ZIP_EOF           (0)
 #define ZIP_ERRNO         (Z_ERRNO)