diff --git a/as400/bndsrc b/as400/bndsrc
index dad2bc9..036cd63 100644
--- a/as400/bndsrc
+++ b/as400/bndsrc
@@ -180,5 +180,6 @@ STRPGMEXP PGMLVL(*CURRENT) SIGNATURE('ZLIB')
   EXPORT SYMBOL("inflatePrime")
   EXPORT SYMBOL("inflateReset2")
   EXPORT SYMBOL("inflateUndermine")
+  EXPORT SYMBOL("inflateResetKeep")
 
 ENDPGMEXP
diff --git a/as400/zlib.inc b/as400/zlib.inc
index 41ff616..976dca2 100644
--- a/as400/zlib.inc
+++ b/as400/zlib.inc
@@ -431,6 +431,10 @@
      D  strm                               like(z_stream)                       Expansion stream
      D  arg                          10I 0 value                                Error code
       *
+     D inflateResetKeep...
+     D                 PR            10I 0 extproc('inflateResetKeep')          End and init. stream
+     D  strm                               like(z_stream)                       Expansion stream
+      *
      D gzflags         PR            10U 0 extproc('gzflags')
       *
       /endif
diff --git a/contrib/vstudio/vc10/zlibvc.def b/contrib/vstudio/vc10/zlibvc.def
index 0d6dc38..d6ab1c1 100644
--- a/contrib/vstudio/vc10/zlibvc.def
+++ b/contrib/vstudio/vc10/zlibvc.def
@@ -128,7 +128,8 @@ EXPORTS
         inflatePrime                            @158
         inflateReset2                           @159
         inflateUndermine                        @160
-
-; zlib1 v1.2.6 added:
-        gzgetc_                                 @30
-        gzflags                                 @162
+
+; zlib1 v1.2.6 added:
+        gzgetc_                                 @30
+        gzflags                                 @162
+        inflateResetKeep                        @163
diff --git a/contrib/vstudio/vc9/zlibvc.def b/contrib/vstudio/vc9/zlibvc.def
index 0d6dc38..d6ab1c1 100644
--- a/contrib/vstudio/vc9/zlibvc.def
+++ b/contrib/vstudio/vc9/zlibvc.def
@@ -128,7 +128,8 @@ EXPORTS
         inflatePrime                            @158
         inflateReset2                           @159
         inflateUndermine                        @160
-
-; zlib1 v1.2.6 added:
-        gzgetc_                                 @30
-        gzflags                                 @162
+
+; zlib1 v1.2.6 added:
+        gzgetc_                                 @30
+        gzflags                                 @162
+        inflateResetKeep                        @163
diff --git a/inflate.c b/inflate.c
index cf10b01..e14b361 100644
--- a/inflate.c
+++ b/inflate.c
@@ -100,7 +100,7 @@ local int updatewindow OF((z_streamp strm, unsigned out));
 local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf,
                               unsigned len));
 
-int ZEXPORT inflateReset(strm)
+int ZEXPORT inflateResetKeep(strm)
 z_streamp strm;
 {
     struct inflate_state FAR *state;
@@ -115,9 +115,6 @@ z_streamp strm;
     state->havedict = 0;
     state->dmax = 32768U;
     state->head = Z_NULL;
-    state->wsize = 0;
-    state->whave = 0;
-    state->wnext = 0;
     state->hold = 0;
     state->bits = 0;
     state->lencode = state->distcode = state->next = state->codes;
@@ -127,6 +124,19 @@ z_streamp strm;
     return Z_OK;
 }
 
+int ZEXPORT inflateReset(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    state->wsize = 0;
+    state->whave = 0;
+    state->wnext = 0;
+    return inflateResetKeep(strm);
+}
+
 int ZEXPORT inflateReset2(strm, windowBits)
 z_streamp strm;
 int windowBits;
diff --git a/win32/zlib.def b/win32/zlib.def
index 93ea8bf..c420d8b 100644
--- a/win32/zlib.def
+++ b/win32/zlib.def
@@ -77,5 +77,6 @@ EXPORTS
     inflateSyncPoint
     get_crc_table
     inflateUndermine
+    inflateResetKeep
     gzgetc_
     gzflags
diff --git a/zconf.h b/zconf.h
index ed16b06..df7ff61 100644
--- a/zconf.h
+++ b/zconf.h
@@ -103,6 +103,7 @@
 #  define inflateSync           z_inflateSync
 #  define inflateSyncPoint      z_inflateSyncPoint
 #  define inflateUndermine      z_inflateUndermine
+#  define inflateResetKeep      z_inflateResetKeep
 #  define inflate_copyright     z_inflate_copyright
 #  define inflate_fast          z_inflate_fast
 #  define inflate_table         z_inflate_table
diff --git a/zconf.h.cmakein b/zconf.h.cmakein
index 84e4680..8450547 100644
--- a/zconf.h.cmakein
+++ b/zconf.h.cmakein
@@ -105,6 +105,7 @@
 #  define inflateSync           z_inflateSync
 #  define inflateSyncPoint      z_inflateSyncPoint
 #  define inflateUndermine      z_inflateUndermine
+#  define inflateResetKeep      z_inflateResetKeep
 #  define inflate_copyright     z_inflate_copyright
 #  define inflate_fast          z_inflate_fast
 #  define inflate_table         z_inflate_table
diff --git a/zconf.h.in b/zconf.h.in
index ed16b06..df7ff61 100644
--- a/zconf.h.in
+++ b/zconf.h.in
@@ -103,6 +103,7 @@
 #  define inflateSync           z_inflateSync
 #  define inflateSyncPoint      z_inflateSyncPoint
 #  define inflateUndermine      z_inflateUndermine
+#  define inflateResetKeep      z_inflateResetKeep
 #  define inflate_copyright     z_inflate_copyright
 #  define inflate_fast          z_inflate_fast
 #  define inflate_table         z_inflate_table
diff --git a/zlib.h b/zlib.h
index 96c2c14..99cd058 100644
--- a/zlib.h
+++ b/zlib.h
@@ -1687,6 +1687,7 @@ ZEXTERN const char   * ZEXPORT zError           OF((int));
 ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp));
 ZEXTERN const uLongf * ZEXPORT get_crc_table    OF((void));
 ZEXTERN int            ZEXPORT inflateUndermine OF((z_streamp, int));
+ZEXTERN int            ZEXPORT inflateResetKeep OF((z_streamp));
 #ifndef Z_SOLO
   ZEXTERN unsigned long  ZEXPORT gzflags          OF((void));
 #endif
diff --git a/zlib.map b/zlib.map
index 627133d..dd27591 100644
--- a/zlib.map
+++ b/zlib.map
@@ -74,4 +74,5 @@ ZLIB_1.2.5.1 {
 ZLIB_1.2.5.2 {
     gzflags;
     gzgetc_;
+    inflateResetKeep;
 } ZLIB_1.2.5.1;