diff --git a/adler32.c b/adler32.c
index 3eafddf..019a233 100644
--- a/adler32.c
+++ b/adler32.c
@@ -60,10 +60,10 @@
 #endif
 
 /* ========================================================================= */
-uLong ZEXPORT adler32(adler, buf, len)
+uLong ZEXPORT adler32_z(adler, buf, len)
     uLong adler;
     const Bytef *buf;
-    uInt len;
+    z_size_t len;
 {
     unsigned long sum2;
     unsigned n;
@@ -131,6 +131,15 @@
 }
 
 /* ========================================================================= */
+uLong ZEXPORT adler32(adler, buf, len)
+    uLong adler;
+    const Bytef *buf;
+    uInt len;
+{
+    return adler32_z(adler, buf, len);
+}
+
+/* ========================================================================= */
 local uLong adler32_combine_(adler1, adler2, len2)
     uLong adler1;
     uLong adler2;
diff --git a/crc32.c b/crc32.c
index d4efea3..ce000ef 100644
--- a/crc32.c
+++ b/crc32.c
@@ -36,9 +36,9 @@
 #endif
 #ifdef BYFOUR
    local unsigned long crc32_little OF((unsigned long,
-                        const unsigned char FAR *, unsigned));
+                        const unsigned char FAR *, z_size_t));
    local unsigned long crc32_big OF((unsigned long,
-                        const unsigned char FAR *, unsigned));
+                        const unsigned char FAR *, z_size_t));
 #  define TBLS 8
 #else
 #  define TBLS 1
@@ -199,10 +199,10 @@
 #define DO8 DO1; DO1; DO1; DO1; DO1; DO1; DO1; DO1
 
 /* ========================================================================= */
-unsigned long ZEXPORT crc32(crc, buf, len)
+unsigned long ZEXPORT crc32_z(crc, buf, len)
     unsigned long crc;
     const unsigned char FAR *buf;
-    uInt len;
+    z_size_t len;
 {
     if (buf == Z_NULL) return 0UL;
 
@@ -233,6 +233,15 @@
     return crc ^ 0xffffffffUL;
 }
 
+/* ========================================================================= */
+unsigned long ZEXPORT crc32(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    uInt len;
+{
+    return crc32_z(crc, buf, len);
+}
+
 #ifdef BYFOUR
 
 /*
@@ -257,7 +266,7 @@
 local unsigned long crc32_little(crc, buf, len)
     unsigned long crc;
     const unsigned char FAR *buf;
-    unsigned len;
+    z_size_t len;
 {
     register z_crc_t c;
     register const z_crc_t FAR *buf4;
@@ -297,7 +306,7 @@
 local unsigned long crc32_big(crc, buf, len)
     unsigned long crc;
     const unsigned char FAR *buf;
-    unsigned len;
+    z_size_t len;
 {
     register z_crc_t c;
     register const z_crc_t FAR *buf4;
diff --git a/zlib.h b/zlib.h
index d831cd7..0f9816d 100644
--- a/zlib.h
+++ b/zlib.h
@@ -1702,6 +1702,12 @@
      if (adler != original_adler) error();
 */
 
+ZEXTERN uLong ZEXPORT adler32_z OF((uLong adler, const Bytef *buf,
+                                    z_size_t len));
+/*
+     Same as adler32(), but with a size_t length.
+*/
+
 /*
 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
                                           z_off_t len2));
@@ -1731,6 +1737,12 @@
      if (crc != original_crc) error();
 */
 
+ZEXTERN uLong ZEXPORT crc32_z OF((uLong adler, const Bytef *buf,
+                                  z_size_t len));
+/*
+     Same as crc32(), but with a size_t length.
+*/
+
 /*
 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));