diff --git a/kmc_api/kmc_file.cpp b/kmc_api/kmc_file.cpp
index fc05547..64c12eb 100644
--- a/kmc_api/kmc_file.cpp
+++ b/kmc_api/kmc_file.cpp
@@ -4,8 +4,8 @@
 
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_api/kmc_file.h b/kmc_api/kmc_file.h
index 0e419cf..b1d0666 100644
--- a/kmc_api/kmc_file.h
+++ b/kmc_api/kmc_file.h
@@ -4,8 +4,8 @@
 
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
  */
 
 #ifndef _KMC_FILE_H
diff --git a/kmc_api/kmer_api.cpp b/kmc_api/kmer_api.cpp
index 13903c7..4e554e6 100644
--- a/kmc_api/kmer_api.cpp
+++ b/kmc_api/kmer_api.cpp
@@ -4,8 +4,8 @@
 
   Authors: Sebastian Deorowicz and Agnieszka Debudaj-Grabysz
 
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 
diff --git a/kmc_api/kmer_api.h b/kmc_api/kmer_api.h
index db17088..2081a88 100644
--- a/kmc_api/kmer_api.h
+++ b/kmc_api/kmer_api.h
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Sebastian Deorowicz and Agnieszka Debudaj-Grabysz
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #ifndef _KMER_API_H
diff --git a/kmc_api/kmer_defs.h b/kmc_api/kmer_defs.h
index acead60..2cbe260 100644
--- a/kmc_api/kmer_defs.h
+++ b/kmc_api/kmer_defs.h
@@ -4,16 +4,16 @@
 
   Authors: Sebastian Deorowicz and Agnieszka Debudaj-Grabysz
 
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 
 #ifndef _KMER_DEFS_H
 #define _KMER_DEFS_H
 
-#define KMC_VER		"3.1.0"
-#define KMC_DATE	"2018-05-10"
+#define KMC_VER		"3.1.1"
+#define KMC_DATE	"2019-05-19"
 
 #ifndef MIN
 #define MIN(x,y)	((x) < (y) ? (x) : (y))
diff --git a/kmc_api/mmer.cpp b/kmc_api/mmer.cpp
index ce1ecec..c2e4250 100644
--- a/kmc_api/mmer.cpp
+++ b/kmc_api/mmer.cpp
@@ -5,8 +5,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "../kmc_api/mmer.h"
diff --git a/kmc_api/mmer.h b/kmc_api/mmer.h
index 3303777..0d64f40 100644
--- a/kmc_api/mmer.h
+++ b/kmc_api/mmer.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _MMER_H
diff --git a/kmc_dump/kmc_dump.cpp b/kmc_dump/kmc_dump.cpp
index 777df64..511e7ee 100644
--- a/kmc_dump/kmc_dump.cpp
+++ b/kmc_dump/kmc_dump.cpp
@@ -7,8 +7,8 @@
 
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_dump/nc_utils.cpp b/kmc_dump/nc_utils.cpp
index 0eee4e0..52c7ff0 100644
--- a/kmc_dump/nc_utils.cpp
+++ b/kmc_dump/nc_utils.cpp
@@ -7,8 +7,8 @@
 
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_dump/nc_utils.h b/kmc_dump/nc_utils.h
index f6dce8e..a682645 100644
--- a/kmc_dump/nc_utils.h
+++ b/kmc_dump/nc_utils.h
@@ -7,8 +7,8 @@
 
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include <string>
diff --git a/kmc_dump_sample/kmc_dump_sample.cpp b/kmc_dump_sample/kmc_dump_sample.cpp
index 0f3ee6a..904f85d 100644
--- a/kmc_dump_sample/kmc_dump_sample.cpp
+++ b/kmc_dump_sample/kmc_dump_sample.cpp
@@ -7,8 +7,8 @@
 
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_tools/bundle.h b/kmc_tools/bundle.h
index 565461c..499cbfa 100644
--- a/kmc_tools/bundle.h
+++ b/kmc_tools/bundle.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _BUNDLE_H
diff --git a/kmc_tools/check_kmer.h b/kmc_tools/check_kmer.h
index cae9975..d130837 100644
--- a/kmc_tools/check_kmer.h
+++ b/kmc_tools/check_kmer.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _CHECK_KMER_H
diff --git a/kmc_tools/config.h b/kmc_tools/config.h
index f689e99..ec7882d 100644
--- a/kmc_tools/config.h
+++ b/kmc_tools/config.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _CONFIG_H
diff --git a/kmc_tools/defs.h b/kmc_tools/defs.h
index 6877237..2eda686 100644
--- a/kmc_tools/defs.h
+++ b/kmc_tools/defs.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _DEFS_H
@@ -30,8 +30,8 @@ using uchar = unsigned char;
 //#define ENABLE_DEBUG
 //#define ENABLE_LOGGER
 
-#define KMC_VER		"3.1.0"
-#define KMC_DATE	"2018-05-10"
+#define KMC_VER		"3.1.1"
+#define KMC_DATE	"2019-05-19"
 
 #define DEFAULT_CIRCULAL_QUEUE_CAPACITY (4)
 
diff --git a/kmc_tools/dump_writer.h b/kmc_tools/dump_writer.h
index 3e7d76f..c0df2ee 100644
--- a/kmc_tools/dump_writer.h
+++ b/kmc_tools/dump_writer.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _DUMP_WRITER_H
diff --git a/kmc_tools/expression_node.h b/kmc_tools/expression_node.h
index 95c7985..be76d01 100644
--- a/kmc_tools/expression_node.h
+++ b/kmc_tools/expression_node.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _EXPRESSION_NODE_H
diff --git a/kmc_tools/fastq_filter.cpp b/kmc_tools/fastq_filter.cpp
index 94ce4db..a42345e 100644
--- a/kmc_tools/fastq_filter.cpp
+++ b/kmc_tools/fastq_filter.cpp
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_tools/fastq_filter.h b/kmc_tools/fastq_filter.h
index 95b27fe..b4d0591 100644
--- a/kmc_tools/fastq_filter.h
+++ b/kmc_tools/fastq_filter.h
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #ifndef _FASTQ_FILTER_H
diff --git a/kmc_tools/fastq_reader.cpp b/kmc_tools/fastq_reader.cpp
index 1f49e1a..b57ec8f 100644
--- a/kmc_tools/fastq_reader.cpp
+++ b/kmc_tools/fastq_reader.cpp
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_tools/fastq_reader.h b/kmc_tools/fastq_reader.h
index ffd3258..1bcb42d 100644
--- a/kmc_tools/fastq_reader.h
+++ b/kmc_tools/fastq_reader.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _FASTQ_READER_H
diff --git a/kmc_tools/fastq_writer.cpp b/kmc_tools/fastq_writer.cpp
index d0fdc21..2dfedb7 100644
--- a/kmc_tools/fastq_writer.cpp
+++ b/kmc_tools/fastq_writer.cpp
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_tools/fastq_writer.h b/kmc_tools/fastq_writer.h
index 10d7d22..5de0186 100644
--- a/kmc_tools/fastq_writer.h
+++ b/kmc_tools/fastq_writer.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _FASTQ_WRITER_H
diff --git a/kmc_tools/histogram_writer.h b/kmc_tools/histogram_writer.h
index dbd8ecb..9601d6a 100644
--- a/kmc_tools/histogram_writer.h
+++ b/kmc_tools/histogram_writer.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _HISTOGRAM_WRITER_H
diff --git a/kmc_tools/kmc1_db_reader.h b/kmc_tools/kmc1_db_reader.h
index 84519d6..1954c6f 100644
--- a/kmc_tools/kmc1_db_reader.h
+++ b/kmc_tools/kmc1_db_reader.h
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #ifndef _KMC1_DB_READER_H
diff --git a/kmc_tools/kmc1_db_writer.h b/kmc_tools/kmc1_db_writer.h
index db23576..18d3099 100644
--- a/kmc_tools/kmc1_db_writer.h
+++ b/kmc_tools/kmc1_db_writer.h
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #ifndef _KMC1_DB_WRITER_H
diff --git a/kmc_tools/kmc2_db_reader.h b/kmc_tools/kmc2_db_reader.h
index 6e2ad8e..de71030 100644
--- a/kmc_tools/kmc2_db_reader.h
+++ b/kmc_tools/kmc2_db_reader.h
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #ifndef _KMC2_DB_READER_H
diff --git a/kmc_tools/kmc_header.cpp b/kmc_tools/kmc_header.cpp
index 65f7092..75c7707 100644
--- a/kmc_tools/kmc_header.cpp
+++ b/kmc_tools/kmc_header.cpp
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_tools/kmc_header.h b/kmc_tools/kmc_header.h
index 06772c3..0a17c5a 100644
--- a/kmc_tools/kmc_header.h
+++ b/kmc_tools/kmc_header.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _KMC_HEADER_H
diff --git a/kmc_tools/kmc_tools.cpp b/kmc_tools/kmc_tools.cpp
index 3baf675..4f992d5 100644
--- a/kmc_tools/kmc_tools.cpp
+++ b/kmc_tools/kmc_tools.cpp
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_tools/kmer.h b/kmc_tools/kmer.h
index 882a150..9a573d9 100644
--- a/kmc_tools/kmer.h
+++ b/kmc_tools/kmer.h
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #ifndef _KMER_H
diff --git a/kmc_tools/meta_oper.h b/kmc_tools/meta_oper.h
index 7eff801..987b12b 100644
--- a/kmc_tools/meta_oper.h
+++ b/kmc_tools/meta_oper.h
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #ifndef _META_OPER_H
diff --git a/kmc_tools/nc_utils.cpp b/kmc_tools/nc_utils.cpp
index 87c3bab..99afd53 100644
--- a/kmc_tools/nc_utils.cpp
+++ b/kmc_tools/nc_utils.cpp
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_tools/nc_utils.h b/kmc_tools/nc_utils.h
index 8dd3606..6df7e55 100644
--- a/kmc_tools/nc_utils.h
+++ b/kmc_tools/nc_utils.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include <string>
diff --git a/kmc_tools/operations.h b/kmc_tools/operations.h
index c4a313b..d8721e0 100644
--- a/kmc_tools/operations.h
+++ b/kmc_tools/operations.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _OPERATIONS_H
diff --git a/kmc_tools/output_parser.h b/kmc_tools/output_parser.h
index 9a70954..46bbfda 100644
--- a/kmc_tools/output_parser.h
+++ b/kmc_tools/output_parser.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _OUTPUT_PARSER_H
diff --git a/kmc_tools/parameters_parser.cpp b/kmc_tools/parameters_parser.cpp
index 27f8692..c7fa99d 100644
--- a/kmc_tools/parameters_parser.cpp
+++ b/kmc_tools/parameters_parser.cpp
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_tools/parameters_parser.h b/kmc_tools/parameters_parser.h
index 84aeac3..7ec0a15 100644
--- a/kmc_tools/parameters_parser.h
+++ b/kmc_tools/parameters_parser.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _PARAMETERS_PARSER_H
diff --git a/kmc_tools/parser.cpp b/kmc_tools/parser.cpp
index 8ffbc07..493ccb5 100644
--- a/kmc_tools/parser.cpp
+++ b/kmc_tools/parser.cpp
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_tools/parser.h b/kmc_tools/parser.h
index 436b09b..0d9992b 100644
--- a/kmc_tools/parser.h
+++ b/kmc_tools/parser.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _PARSER_H
diff --git a/kmc_tools/percent_progress.cpp b/kmc_tools/percent_progress.cpp
index 0b8a23b..c50ec49 100644
--- a/kmc_tools/percent_progress.cpp
+++ b/kmc_tools/percent_progress.cpp
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmc_tools/percent_progress.h b/kmc_tools/percent_progress.h
index 9a31de8..15d0313 100644
--- a/kmc_tools/percent_progress.h
+++ b/kmc_tools/percent_progress.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _PERCENT_PROGRESS_H
diff --git a/kmc_tools/queues.h b/kmc_tools/queues.h
index 99800e2..cd64ee3 100644
--- a/kmc_tools/queues.h
+++ b/kmc_tools/queues.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _QUEUES_H_
diff --git a/kmc_tools/thread_watch.h b/kmc_tools/thread_watch.h
index a27b295..3023b4c 100644
--- a/kmc_tools/thread_watch.h
+++ b/kmc_tools/thread_watch.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _THREAD_WATCH_H
diff --git a/kmc_tools/timer.h b/kmc_tools/timer.h
index e906488..b7d96f6 100644
--- a/kmc_tools/timer.h
+++ b/kmc_tools/timer.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _TIMER_H
diff --git a/kmc_tools/tokenizer.cpp b/kmc_tools/tokenizer.cpp
index 71d7c9f..b5154de 100644
--- a/kmc_tools/tokenizer.cpp
+++ b/kmc_tools/tokenizer.cpp
@@ -4,7 +4,7 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
+  Version: 3.1.1
   Date   : 2017-01-28
 */
 
diff --git a/kmc_tools/tokenizer.h b/kmc_tools/tokenizer.h
index 7e72807..1c07596 100644
--- a/kmc_tools/tokenizer.h
+++ b/kmc_tools/tokenizer.h
@@ -4,8 +4,8 @@
   
   Authors: Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _TOKENIZER_H
diff --git a/kmer_counter/bam_utils.h b/kmer_counter/bam_utils.h
index 38b0470..2b2f643 100644
--- a/kmer_counter/bam_utils.h
+++ b/kmer_counter/bam_utils.h
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #ifndef _BAM_UTILS_H
diff --git a/kmer_counter/binary_reader.h b/kmer_counter/binary_reader.h
index 0ef3e81..e33a3af 100644
--- a/kmer_counter/binary_reader.h
+++ b/kmer_counter/binary_reader.h
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #ifndef _BINARY_READER_H
diff --git a/kmer_counter/bkb_merger.h b/kmer_counter/bkb_merger.h
index f21a8b4..1597c32 100644
--- a/kmer_counter/bkb_merger.h
+++ b/kmer_counter/bkb_merger.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _HBH_MERGER_H
diff --git a/kmer_counter/bkb_reader.cpp b/kmer_counter/bkb_reader.cpp
index 267f349..e40a3be 100644
--- a/kmer_counter/bkb_reader.cpp
+++ b/kmer_counter/bkb_reader.cpp
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmer_counter/bkb_reader.h b/kmer_counter/bkb_reader.h
index fbe0e02..2e4115c 100644
--- a/kmer_counter/bkb_reader.h
+++ b/kmer_counter/bkb_reader.h
@@ -5,8 +5,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #ifndef _BKB_READER_H_
diff --git a/kmer_counter/bkb_sorter.h b/kmer_counter/bkb_sorter.h
index 1bb2641..4f8d89b 100644
--- a/kmer_counter/bkb_sorter.h
+++ b/kmer_counter/bkb_sorter.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _BKB_SORTER_H
diff --git a/kmer_counter/bkb_subbin.h b/kmer_counter/bkb_subbin.h
index c9c39b3..841e853 100644
--- a/kmer_counter/bkb_subbin.h
+++ b/kmer_counter/bkb_subbin.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _BKB_SUBBIN_H
diff --git a/kmer_counter/bkb_uncompactor.h b/kmer_counter/bkb_uncompactor.h
index 92eb2a3..5dc27ce 100644
--- a/kmer_counter/bkb_uncompactor.h
+++ b/kmer_counter/bkb_uncompactor.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _BKB_UNCOMPACTOR_H
diff --git a/kmer_counter/bkb_writer.cpp b/kmer_counter/bkb_writer.cpp
index 2648bf9..29d0e8a 100644
--- a/kmer_counter/bkb_writer.cpp
+++ b/kmer_counter/bkb_writer.cpp
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmer_counter/bkb_writer.h b/kmer_counter/bkb_writer.h
index 5c3698d..bcec25e 100644
--- a/kmer_counter/bkb_writer.h
+++ b/kmer_counter/bkb_writer.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _BKB_WRITER_H
diff --git a/kmer_counter/cpu_info.cpp b/kmer_counter/cpu_info.cpp
index e13438e..053b324 100644
--- a/kmer_counter/cpu_info.cpp
+++ b/kmer_counter/cpu_info.cpp
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmer_counter/cpu_info.h b/kmer_counter/cpu_info.h
index 4083721..0767c59 100644
--- a/kmer_counter/cpu_info.h
+++ b/kmer_counter/cpu_info.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _CPU_INFO_
diff --git a/kmer_counter/defs.h b/kmer_counter/defs.h
index e2e49a8..6f9a095 100644
--- a/kmer_counter/defs.h
+++ b/kmer_counter/defs.h
@@ -4,15 +4,15 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _DEFS_H
 #define _DEFS_H
 
-#define KMC_VER		"3.1.0"
-#define KMC_DATE	"2018-05-10"
+#define KMC_VER		"3.1.1"
+#define KMC_DATE	"2019-05-19"
 
 #define _CRT_SECURE_NO_WARNINGS
 
diff --git a/kmer_counter/fastq_reader.cpp b/kmer_counter/fastq_reader.cpp
index abb1924..853d336 100644
--- a/kmer_counter/fastq_reader.cpp
+++ b/kmer_counter/fastq_reader.cpp
@@ -5,8 +5,8 @@
 
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include <algorithm>
diff --git a/kmer_counter/fastq_reader.h b/kmer_counter/fastq_reader.h
index 0510473..9afab1b 100644
--- a/kmer_counter/fastq_reader.h
+++ b/kmer_counter/fastq_reader.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _FASTQ_READER_H
diff --git a/kmer_counter/first_dispatch.h b/kmer_counter/first_dispatch.h
index 5e2b085..1608ac0 100644
--- a/kmer_counter/first_dispatch.h
+++ b/kmer_counter/first_dispatch.h
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 #ifndef _FIRST_DISPATCH_H
 #define _FIRST_DISPATCH_H
diff --git a/kmer_counter/intr_copy.h b/kmer_counter/intr_copy.h
index e747137..4c6316a 100644
--- a/kmer_counter/intr_copy.h
+++ b/kmer_counter/intr_copy.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _INTR_COPY_H
diff --git a/kmer_counter/kb_collector.cpp b/kmer_counter/kb_collector.cpp
index 0283f00..675b6a2 100644
--- a/kmer_counter/kb_collector.cpp
+++ b/kmer_counter/kb_collector.cpp
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmer_counter/kb_collector.h b/kmer_counter/kb_collector.h
index 5f05a0b..cd1592d 100644
--- a/kmer_counter/kb_collector.h
+++ b/kmer_counter/kb_collector.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _KB_COLLECTOR_H
diff --git a/kmer_counter/kb_completer.cpp b/kmer_counter/kb_completer.cpp
index 2a12b43..655a789 100644
--- a/kmer_counter/kb_completer.cpp
+++ b/kmer_counter/kb_completer.cpp
@@ -5,8 +5,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 #include <algorithm>
 #include <numeric>
diff --git a/kmer_counter/kb_completer.h b/kmer_counter/kb_completer.h
index c77f2ea..fc62aed 100644
--- a/kmer_counter/kb_completer.h
+++ b/kmer_counter/kb_completer.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 #ifndef _KB_COMPLETER_H
 #define _KB_COMPLETER_H
diff --git a/kmer_counter/kb_reader.h b/kmer_counter/kb_reader.h
index e6d1ec8..e190763 100644
--- a/kmer_counter/kb_reader.h
+++ b/kmer_counter/kb_reader.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _KB_READER_H
diff --git a/kmer_counter/kb_sorter.h b/kmer_counter/kb_sorter.h
index 9026b2e..599e37f 100644
--- a/kmer_counter/kb_sorter.h
+++ b/kmer_counter/kb_sorter.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _KB_SORTER_H
diff --git a/kmer_counter/kb_storer.cpp b/kmer_counter/kb_storer.cpp
index 91d78b8..bb368f6 100644
--- a/kmer_counter/kb_storer.cpp
+++ b/kmer_counter/kb_storer.cpp
@@ -5,8 +5,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 #include <algorithm>
 #include <numeric>
diff --git a/kmer_counter/kb_storer.h b/kmer_counter/kb_storer.h
index 4898bd1..c3b39c0 100644
--- a/kmer_counter/kb_storer.h
+++ b/kmer_counter/kb_storer.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _KB_STORER_H
diff --git a/kmer_counter/kmc.h b/kmer_counter/kmc.h
index aa854ba..068015a 100644
--- a/kmer_counter/kmc.h
+++ b/kmer_counter/kmc.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _KMC_H
diff --git a/kmer_counter/kmer.cpp b/kmer_counter/kmer.cpp
index 9ff2bb6..cd88ba9 100644
--- a/kmer_counter/kmer.cpp
+++ b/kmer_counter/kmer.cpp
@@ -5,8 +5,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "defs.h"
diff --git a/kmer_counter/kmer.h b/kmer_counter/kmer.h
index d106f5d..c4589c3 100644
--- a/kmer_counter/kmer.h
+++ b/kmer_counter/kmer.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _KMER_H
diff --git a/kmer_counter/kmer_counter.cpp b/kmer_counter/kmer_counter.cpp
index 3583f66..e8f7891 100644
--- a/kmer_counter/kmer_counter.cpp
+++ b/kmer_counter/kmer_counter.cpp
@@ -5,8 +5,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include <fstream>
diff --git a/kmer_counter/kxmer_set.h b/kmer_counter/kxmer_set.h
index dd12d71..ba6434f 100644
--- a/kmer_counter/kxmer_set.h
+++ b/kmer_counter/kxmer_set.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 #ifndef _KXMER_SET_
 #define _KXMER_SET_
diff --git a/kmer_counter/mem_disk_file.cpp b/kmer_counter/mem_disk_file.cpp
index 6319992..dc45435 100644
--- a/kmer_counter/mem_disk_file.cpp
+++ b/kmer_counter/mem_disk_file.cpp
@@ -5,8 +5,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "mem_disk_file.h"
diff --git a/kmer_counter/mem_disk_file.h b/kmer_counter/mem_disk_file.h
index 5dd4d91..dd90d7e 100644
--- a/kmer_counter/mem_disk_file.h
+++ b/kmer_counter/mem_disk_file.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _MEM_DISK_FILE_H
diff --git a/kmer_counter/meta_oper.h b/kmer_counter/meta_oper.h
index df2161c..990680a 100644
--- a/kmer_counter/meta_oper.h
+++ b/kmer_counter/meta_oper.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _META_OPER_H
diff --git a/kmer_counter/mmer.cpp b/kmer_counter/mmer.cpp
index 9b179ee..a690a14 100644
--- a/kmer_counter/mmer.cpp
+++ b/kmer_counter/mmer.cpp
@@ -5,8 +5,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "mmer.h"
diff --git a/kmer_counter/mmer.h b/kmer_counter/mmer.h
index 7d92b0c..fa00568 100644
--- a/kmer_counter/mmer.h
+++ b/kmer_counter/mmer.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _MMER_H
diff --git a/kmer_counter/params.h b/kmer_counter/params.h
index d12b9c8..a9d9495 100644
--- a/kmer_counter/params.h
+++ b/kmer_counter/params.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _PARAMS_H
diff --git a/kmer_counter/percent_progress.h b/kmer_counter/percent_progress.h
index a52b18c..415cc42 100644
--- a/kmer_counter/percent_progress.h
+++ b/kmer_counter/percent_progress.h
@@ -5,7 +5,7 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
 Version: 3.0.0
-Date   : 2018-05-10
+Date   : 2019-05-19
 */
 
 #ifndef _PERCENT_PROGRESS_H
diff --git a/kmer_counter/queues.h b/kmer_counter/queues.h
index cc2db51..23eca41 100644
--- a/kmer_counter/queues.h
+++ b/kmer_counter/queues.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _QUEUES_H
diff --git a/kmer_counter/radix.h b/kmer_counter/radix.h
index 42f7b36..5ca7dc3 100644
--- a/kmer_counter/radix.h
+++ b/kmer_counter/radix.h
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.
+Date   : 2019-05-19
 */
 #ifndef _RADIX_H
 #define _RADIX_H
diff --git a/kmer_counter/raduls.h b/kmer_counter/raduls.h
index 478be2b..f22d8a2 100644
--- a/kmer_counter/raduls.h
+++ b/kmer_counter/raduls.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef RADULS_H
diff --git a/kmer_counter/raduls_avx.cpp b/kmer_counter/raduls_avx.cpp
index b8b34dc..971161f 100644
--- a/kmer_counter/raduls_avx.cpp
+++ b/kmer_counter/raduls_avx.cpp
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmer_counter/raduls_avx2.cpp b/kmer_counter/raduls_avx2.cpp
index b8b34dc..971161f 100644
--- a/kmer_counter/raduls_avx2.cpp
+++ b/kmer_counter/raduls_avx2.cpp
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmer_counter/raduls_impl.h b/kmer_counter/raduls_impl.h
index 88101ff..fac4e78 100644
--- a/kmer_counter/raduls_impl.h
+++ b/kmer_counter/raduls_impl.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _RADULS_IMPL_H
diff --git a/kmer_counter/raduls_sse2.cpp b/kmer_counter/raduls_sse2.cpp
index b8b34dc..971161f 100644
--- a/kmer_counter/raduls_sse2.cpp
+++ b/kmer_counter/raduls_sse2.cpp
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmer_counter/raduls_sse41.cpp b/kmer_counter/raduls_sse41.cpp
index b8b34dc..971161f 100644
--- a/kmer_counter/raduls_sse41.cpp
+++ b/kmer_counter/raduls_sse41.cpp
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmer_counter/rev_byte.cpp b/kmer_counter/rev_byte.cpp
index c8c9599..1421f26 100644
--- a/kmer_counter/rev_byte.cpp
+++ b/kmer_counter/rev_byte.cpp
@@ -5,8 +5,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #include "rev_byte.h"
diff --git a/kmer_counter/rev_byte.h b/kmer_counter/rev_byte.h
index 4a1a237..44e9a4f 100644
--- a/kmer_counter/rev_byte.h
+++ b/kmer_counter/rev_byte.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _REV_BYTE_H
diff --git a/kmer_counter/s_mapper.h b/kmer_counter/s_mapper.h
index ba6e38e..bfd84bf 100644
--- a/kmer_counter/s_mapper.h
+++ b/kmer_counter/s_mapper.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _S_MAPPER_H
diff --git a/kmer_counter/small_k_buf.h b/kmer_counter/small_k_buf.h
index 029abcf..51fd2ef 100644
--- a/kmer_counter/small_k_buf.h
+++ b/kmer_counter/small_k_buf.h
@@ -4,7 +4,7 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
+  Version: 3.1.1
   Date   : 2017-01-28
 */
 
diff --git a/kmer_counter/small_sort.h b/kmer_counter/small_sort.h
index 6567ea1..bc0dd76 100644
--- a/kmer_counter/small_sort.h
+++ b/kmer_counter/small_sort.h
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 #ifndef _SMALL_SORT_H
 #define _SMALL_SORT_H
diff --git a/kmer_counter/splitter.cpp b/kmer_counter/splitter.cpp
index 47cf258..48391a6 100644
--- a/kmer_counter/splitter.cpp
+++ b/kmer_counter/splitter.cpp
@@ -4,8 +4,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 
 Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #include "stdafx.h"
diff --git a/kmer_counter/splitter.h b/kmer_counter/splitter.h
index 74331b2..c6bd082 100644
--- a/kmer_counter/splitter.h
+++ b/kmer_counter/splitter.h
@@ -4,8 +4,8 @@
   
   Authors: Sebastian Deorowicz, Agnieszka Debudaj-Grabysz, Marek Kokot
   
-  Version: 3.1.0
-  Date   : 2018-05-10
+  Version: 3.1.1
+  Date   : 2019-05-19
 */
 
 #ifndef _SPLITTER_H
diff --git a/kmer_counter/timer.cpp b/kmer_counter/timer.cpp
index 67c9056..dcb2418 100644
--- a/kmer_counter/timer.cpp
+++ b/kmer_counter/timer.cpp
@@ -6,8 +6,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 The source codes are based on codes written by Dennis and published:
 http://allmybrain.com/2008/06/10/timing-cc-code-on-linux/
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #ifdef WIN32
diff --git a/kmer_counter/timer.h b/kmer_counter/timer.h
index 4819c48..6b72c81 100644
--- a/kmer_counter/timer.h
+++ b/kmer_counter/timer.h
@@ -5,8 +5,8 @@ The homepage of the KMC project is http://sun.aei.polsl.pl/kmc
 The source codes are based on codes written by Dennis and published:
 http://allmybrain.com/2008/06/10/timing-cc-code-on-linux/
 
-Version: 3.1.0
-Date   : 2018-05-10
+Version: 3.1.1
+Date   : 2019-05-19
 */
 
 #ifndef _TIMER_H
diff --git a/py_kmc_api/py_kmc_dump.py b/py_kmc_api/py_kmc_dump.py
index 4f9a32b..a14e87e 100644
--- a/py_kmc_api/py_kmc_dump.py
+++ b/py_kmc_api/py_kmc_dump.py
@@ -4,8 +4,8 @@
 import argparse
 import textwrap
 
-VER = "3.1.0"
-DATE = "2018-12-29"
+VER = "3.1.1"
+DATE = "2019-05-19"
 
 def GeneralHelp():
     print('KMC dump ver. {} ({})'.format(VER, DATE))