diff --git a/libknet/compress_zlib.c b/libknet/compress_zlib.c
index 0256e081..fbf4b3ba 100644
--- a/libknet/compress_zlib.c
+++ b/libknet/compress_zlib.c
@@ -1,128 +1,128 @@
 /*
  * Copyright (C) 2010-2017 Red Hat, Inc.  All rights reserved.
  *
  * Author: Fabio M. Di Nitto <fabbione@kronosnet.org>
  *
  * This software licensed under GPL-2.0+, LGPL-2.0+
  */
 
 #include "config.h"
 
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
 #include <zlib.h>
 
 #include "internals.h"
 #include "compress_zlib.h"
 #include "logging.h"
 
 int zlib_val_level(
 	knet_handle_t knet_h,
 	int compress_level)
 {
 	if (compress_level < 0) {
 		log_err(knet_h, KNET_SUB_ZLIBCOMP, "zlib does not support negative compression level %d",
 			 compress_level);
 		return -1;
 	}
 	if (compress_level > 9) {
 		log_err(knet_h, KNET_SUB_ZLIBCOMP, "zlib does not support compression level higher than 9");
 		return -1;
 	}
 	if (compress_level == 0) {
 		log_warn(knet_h, KNET_SUB_ZLIBCOMP, "zlib compress level 0 does NOT perform any compression");
 	}
 	return 0;
 }
 
 int zlib_compress(
 	knet_handle_t knet_h,
 	const unsigned char *buf_in,
 	const ssize_t buf_in_len,
 	unsigned char *buf_out,
 	ssize_t *buf_out_len)
 {
 	int zerr = 0, err = 0;
 	int savederrno = 0;
 	uLongf destLen = *buf_out_len;
 
 	zerr = compress2(buf_out, &destLen,
 			 buf_in, buf_in_len,
 			 knet_h->compress_level);
 
 	*buf_out_len = destLen;
 
 	switch(zerr) {
 		case Z_OK:
 			err = 0;
 			savederrno = 0;
 			break;
 		case Z_MEM_ERROR:
-			log_debug(knet_h, KNET_SUB_ZLIBCOMP, "zlib compress mem error");
+			log_err(knet_h, KNET_SUB_ZLIBCOMP, "zlib compress mem error");
 			err = -1; 
 			savederrno = ENOMEM;
 			break;
 		case Z_BUF_ERROR:
-			log_debug(knet_h, KNET_SUB_ZLIBCOMP, "zlib compress buf error");
+			log_err(knet_h, KNET_SUB_ZLIBCOMP, "zlib compress buf error");
 			err = -1;
 			savederrno = ENOBUFS;
 			break;
 		case Z_STREAM_ERROR:
-			log_debug(knet_h, KNET_SUB_ZLIBCOMP, "zlib compress stream error");
+			log_err(knet_h, KNET_SUB_ZLIBCOMP, "zlib compress stream error");
 			err = -1;
 			savederrno = EINVAL;
 			break;
 		default:
-			log_debug(knet_h, KNET_SUB_ZLIBCOMP, "zlib compress unknown error");
+			log_err(knet_h, KNET_SUB_ZLIBCOMP, "zlib unknown compress error: %d", zerr);
 			break;
 	}
 
 	errno = savederrno;
 	return err;
 }
 
 int zlib_decompress(
 	knet_handle_t knet_h,
 	const unsigned char *buf_in,
 	const ssize_t buf_in_len,
 	unsigned char *buf_out,
 	ssize_t *buf_out_len)
 {
 	int zerr = 0, err = 0;
 	int savederrno = 0;
 	uLongf destLen = *buf_out_len;
 
 	zerr = uncompress(buf_out, &destLen,
 			  buf_in, buf_in_len);
 
 	*buf_out_len = destLen;
 
 	switch(zerr) {
 		case Z_OK:
 			err = 0;
 			savederrno = 0;
 			break;
 		case Z_MEM_ERROR:
-			log_debug(knet_h, KNET_SUB_ZLIBCOMP, "zlib decompress mem error");
+			log_err(knet_h, KNET_SUB_ZLIBCOMP, "zlib decompress mem error");
 			err = -1;
 			savederrno = ENOMEM;
 			break;
 		case Z_BUF_ERROR:
-			log_debug(knet_h, KNET_SUB_ZLIBCOMP, "zlib decompress buf error");
+			log_err(knet_h, KNET_SUB_ZLIBCOMP, "zlib decompress buf error");
 			err = -1;
 			savederrno = ENOBUFS;
 			break;
 		case Z_DATA_ERROR:
-			log_debug(knet_h, KNET_SUB_ZLIBCOMP, "zlib decompress data error");
+			log_err(knet_h, KNET_SUB_ZLIBCOMP, "zlib decompress data error");
 			err = -1;
 			savederrno = EINVAL;
 			break;
 		default:
-			log_debug(knet_h, KNET_SUB_ZLIBCOMP, "zlib unknown error");
+			log_err(knet_h, KNET_SUB_ZLIBCOMP, "zlib unknown decompress error: %d", zerr);
 			break;
 	}
 
 	errno = savederrno;
 	return err;
 }