1 files changed, 5 insertions, 1 deletions
diff --git a/ext/zlib/zlib.c b/ext/zlib/zlib.c
index 17f132b1b1..d5909d60c0 100644
--- a/ext/zlib/zlib.c
+++ b/ext/zlib/zlib.c
@@ -464,7 +464,11 @@ rb_zlib_crc32_combine(VALUE klass, VALUE crc1, VALUE crc2, VALUE len2)
 static VALUE
 rb_zlib_crc_table(VALUE obj)
 {
-    const unsigned long *crctbl;
+#if !defined(HAVE_TYPE_Z_CRC_T)
+    /* z_crc_t is defined since zlib-1.2.7. */
+    typedef unsigned long z_crc_t;
+#endif
+    const z_crc_t *crctbl;
     VALUE dst;
     int i;