diff --git a/deps/rzlib/gzguts.h b/deps/rzlib/gzguts.h
index cb7352e2e4..1fc2caa357 100644
--- a/deps/rzlib/gzguts.h
+++ b/deps/rzlib/gzguts.h
@@ -132,10 +132,14 @@
 
 /* provide prototypes for these when building zlib without LFS */
 #if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
-    ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
-    ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
-    ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
-    ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
+#ifndef z_off64_t
+#define z_off64_t z_off_t
+#endif
+
+    gzFile gzopen64 OF((const char *, const char *));
+    z_off64_t gzseek64 OF((gzFile, z_off64_t, int));
+    z_off64_t gztell64 OF((gzFile));
+    z_off64_t gzoffset64 OF((gzFile));
 #endif
 
 /* default memLevel */
diff --git a/deps/rzlib/inflate.c b/deps/rzlib/inflate.c
index b65283ac45..4213615636 100644
--- a/deps/rzlib/inflate.c
+++ b/deps/rzlib/inflate.c
@@ -91,6 +91,10 @@
 #  endif
 #endif
 
+#ifndef Z_TREES
+#define Z_TREES 6
+#endif
+
 /* function prototypes */
 local void fixedtables OF((struct inflate_state FAR *state));
 local int updatewindow OF((z_streamp strm, const unsigned char FAR *end,