diff --git a/src/tools/docbook/libxml2/xmlIO.c b/src/tools/docbook/libxml2/xmlIO.c
index 60e0a50ae3..2d614195da 100644
--- a/src/tools/docbook/libxml2/xmlIO.c
+++ b/src/tools/docbook/libxml2/xmlIO.c
@@ -2298,6 +2298,9 @@ __xmlParserInputBufferCreateFilename(const char *URI, xmlCharEncoding enc) {
 #ifdef HAVE_ZLIB_H
 	if ((xmlInputCallbackTable[i].opencallback == xmlGzfileOpen) &&
 		(strcmp(URI, "-") != 0)) {
+#if defined(ZLIB_VERNUM) && ZLIB_VERNUM >= 0x1230
+		ret->compressed = !gzdirect(context);
+#else
 	    if (((z_stream *)context)->avail_in > 4) {
 	        char *cptr, buff4[4];
 		cptr = (char *) ((z_stream *)context)->next_in;
@@ -2309,6 +2312,7 @@ __xmlParserInputBufferCreateFilename(const char *URI, xmlCharEncoding enc) {
 		    gzrewind(context);
 		}
 	    }
+#endif
 	}
 #endif
     }