diff --git a/man/swarm.1 b/man/swarm.1
index 1b9c51b5..9874c8fb 100644
--- a/man/swarm.1
+++ b/man/swarm.1
@@ -1,5 +1,5 @@
 .\" ============================================================================
-.TH swarm 1 "February 24, 2016" "version 2.1.6" "USER COMMANDS"
+.TH swarm 1 "February 24, 2016" "version 2.1.7" "USER COMMANDS"
 .\" ============================================================================
 .SH NAME
 swarm \(em find clusters of nearly-identical nucleotide amplicons
@@ -279,11 +279,11 @@ Concept by Frédéric Mahé, implementation by Torbjørn Rognes.
 .SH CITATION
 Mahé F, Rognes T, Quince C, de Vargas C, Dunthorn M. (2014)
 Swarm: robust and fast clustering method for amplicon-based studies.
-\fIPeerJ\fR 2:e593 <http://dx.doi.org/10.7717/peerj.593>
+\fIPeerJ\fR 2:e593 <https://doi.org/10.7717/peerj.593>
 .PP
 Mahé F, Rognes T, Quince C, de Vargas C, Dunthorn M. (2015)
 Swarm v2: highly-scalable and high-resolution amplicon clustering.
-\fIPeerJ\fR 3:e1420 <http://dx.doi.org/10.7717/peerj.1420>
+\fIPeerJ\fR 3:e1420 <https://doi.org/10.7717/peerj.1420>
 .\" ============================================================================
 .SH REPORTING BUGS
 Submit suggestions and bug-reports at
@@ -296,7 +296,7 @@ Torbjørn Rognes <torognes@ifi.uio.no>.
 The software is available from <https://github.com/torognes/swarm>
 .\" ============================================================================
 .SH COPYRIGHT
-Copyright (C) 2012, 2013, 2014, 2015, 2016 Frédéric Mahé & Torbjørn Rognes
+Copyright (C) 2012-2016 Frédéric Mahé & Torbjørn Rognes
 .PP
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU Affero General Public License as
@@ -329,10 +329,17 @@ New features and important modifications of \fBswarm\fR (short lived
 or minor bug releases are not mentioned):
 .RS
 .TP
+.BR v2.1.7\~ "released February 24, 2016"
+Version 2.1.7 fixes a bug in the output of seeds with the \-w option
+when \fId\fR > 1 that was not properly fixed in version 2.1.6. It also
+handles ascii character no 13 (CR) in FASTA files better. Swarm will
+now exit with status 0 if the \-h or the \-v option is specified. The
+help text and some error messages have been improved.
+.TP
 .BR v2.1.6\~ "released December 14, 2015"
 Version 2.1.6 fixes problems with older compilers that do not have the
 x86intrin.h header file. It also fixes a bug in the output of seeds
-with the `-w` option when \fId\fR > 1.
+with the \-w option when \fId\fR > 1.
 .TP
 .BR v2.1.5\~ "released September 8, 2015"
 Version 2.1.5 fixes minor bugs.
diff --git a/man/swarm_manual.pdf b/man/swarm_manual.pdf
index 4da63529..c9d0ba47 100644
Binary files a/man/swarm_manual.pdf and b/man/swarm_manual.pdf differ
diff --git a/src/Makefile b/src/Makefile
index 174808f9..407ebe68 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1,6 +1,6 @@
 # SWARM
 #
-# Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe
+# Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 # 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as
diff --git a/src/algo.cc b/src/algo.cc
index 75a57008..31741924 100644
--- a/src/algo.cc
+++ b/src/algo.cc
@@ -1,24 +1,24 @@
 /*
-  SWARM
+    SWARM
 
-  Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
-  This program is free software: you can redistribute it and/or modify
-  it under the terms of the GNU Affero General Public License as
-  published by the Free Software Foundation, either version 3 of the
-  License, or (at your option) any later version.
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as
+    published by the Free Software Foundation, either version 3 of the
+    License, or (at your option) any later version.
 
-  This program is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU Affero General Public License for more details.
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
 
-  You should have received a copy of the GNU Affero General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-  Contact: Torbjorn Rognes <torognes@ifi.uio.no>,
-  Department of Informatics, University of Oslo,
-  PO Box 1080 Blindern, NO-0316 Oslo, Norway
+    Contact: Torbjorn Rognes <torognes@ifi.uio.no>,
+    Department of Informatics, University of Oslo,
+    PO Box 1080 Blindern, NO-0316 Oslo, Norway
 */
 
 #include "swarm.h"
@@ -515,9 +515,8 @@ void algo_run()
 
       unsigned long mass = 0;
       unsigned previd = amps[0].swarmid;
-      unsigned prevamp = amps[0].ampliconid;
-      unsigned seed = prevamp;
-      mass += db_getabundance(prevamp);
+      unsigned seed = amps[0].ampliconid;
+      mass += db_getabundance(seed);
 
       for (unsigned long i=1; i<amplicons; i++)
         {
@@ -528,21 +527,21 @@ void algo_run()
               fprintf(fp_seeds, ">");
               fprint_id_with_new_abundance(fp_seeds, seed, mass);
               fprintf(fp_seeds, "\n");
-              db_fprintseq(fp_seeds, prevamp, 0);
+              db_fprintseq(fp_seeds, seed, 0);
+
               mass = 0;
               seed = amps[i].ampliconid;
             }
 
+          mass += db_getabundance(amps[i].ampliconid);
           previd = id;
-          prevamp = amps[i].ampliconid;
-          mass += db_getabundance(prevamp);
           progress_update(i);
         }
 
       fprintf(fp_seeds, ">");
       fprint_id_with_new_abundance(fp_seeds, seed, mass);
       fprintf(fp_seeds, "\n");
-      db_fprintseq(fp_seeds, prevamp, 0);
+      db_fprintseq(fp_seeds, seed, 0);
 
       progress_done();
     }
diff --git a/src/algod1.cc b/src/algod1.cc
index f7f4cc06..57336e92 100644
--- a/src/algod1.cc
+++ b/src/algod1.cc
@@ -1,30 +1,30 @@
 /*
-  SWARM
+    SWARM
 
-  Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
-  This program is free software: you can redistribute it and/or modify
-  it under the terms of the GNU Affero General Public License as
-  published by the Free Software Foundation, either version 3 of the
-  License, or (at your option) any later version.
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as
+    published by the Free Software Foundation, either version 3 of the
+    License, or (at your option) any later version.
 
-  This program is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU Affero General Public License for more details.
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
 
-  You should have received a copy of the GNU Affero General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-  Contact: Torbjorn Rognes <torognes@ifi.uio.no>,
-  Department of Informatics, University of Oslo,
-  PO Box 1080 Blindern, NO-0316 Oslo, Norway
+    Contact: Torbjorn Rognes <torognes@ifi.uio.no>,
+    Department of Informatics, University of Oslo,
+    PO Box 1080 Blindern, NO-0316 Oslo, Norway
 */
 
 /*
   This version of the swarm algorithm uses Frederic's idea for d=1 to
-  enumerate all of the maximum 7L+4 possible variants of a sequence with only
-  one difference, where L is the length of the sequence.
+  enumerate all of the maximum 7L+4 possible variants of a sequence
+  with only one difference, where L is the length of the sequence.
 */
 
 #include "swarm.h"
diff --git a/src/arch.cc b/src/arch.cc
index 3959723d..e223c926 100644
--- a/src/arch.cc
+++ b/src/arch.cc
@@ -1,5 +1,7 @@
 /*
-    Copyright (C) 2014-2015 Torbjorn Rognes
+    SWARM
+
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
diff --git a/src/bitmap.h b/src/bitmap.h
index f07ed3fd..429afac7 100644
--- a/src/bitmap.h
+++ b/src/bitmap.h
@@ -1,5 +1,7 @@
 /*
-    Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe
+    SWARM
+
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
diff --git a/src/bloom.h b/src/bloom.h
index aab69087..95c72ce9 100644
--- a/src/bloom.h
+++ b/src/bloom.h
@@ -1,5 +1,7 @@
 /*
-    Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe
+    SWARM
+
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
diff --git a/src/db.cc b/src/db.cc
index eeee70df..56df3e5b 100644
--- a/src/db.cc
+++ b/src/db.cc
@@ -1,24 +1,24 @@
 /*
-  SWARM
+    SWARM
 
-  Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
-  This program is free software: you can redistribute it and/or modify
-  it under the terms of the GNU Affero General Public License as
-  published by the Free Software Foundation, either version 3 of the
-  License, or (at your option) any later version.
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as
+    published by the Free Software Foundation, either version 3 of the
+    License, or (at your option) any later version.
 
-  This program is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU Affero General Public License for more details.
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
 
-  You should have received a copy of the GNU Affero General Public License
-  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-  Contact: Torbjorn Rognes <torognes@ifi.uio.no>,
-  Department of Informatics, University of Oslo,
-  PO Box 1080 Blindern, NO-0316 Oslo, Norway
+    Contact: Torbjorn Rognes <torognes@ifi.uio.no>,
+    Department of Informatics, University of Oslo,
+    PO Box 1080 Blindern, NO-0316 Oslo, Norway
 */
 
 #include "swarm.h"
@@ -215,7 +215,7 @@ void db_read(const char * filename)
         fatal("Illegal header line in fasta file.");
       
       long headerlen = 0;
-      if (char * stop = strpbrk(line+1, " \n"))
+      if (char * stop = strpbrk(line+1, " \r\n"))
         headerlen = stop - (line+1);
       else
         headerlen = strlen(line+1);
@@ -278,10 +278,13 @@ void db_read(const char * filename)
                 *(datap+datalen) = m;
                 datalen++;
               }
-            else if (c != '\n')
+            else if ((c != 10) && (c != 13))
               {
                 char msg[100];
-                snprintf(msg, 100, "Illegal character '%c' in sequence on line %u", c, lineno);
+                if ((c >= 32) && (c <= 126))
+                  snprintf(msg, 100, "Illegal character '%c' in sequence on line %u", c, lineno);
+                else
+                  snprintf(msg, 100, "Illegal character (ascii no %d) in sequence on line %u", c, lineno);
                 fatal(msg);
               }
           line[0] = 0;
@@ -434,12 +437,10 @@ void db_read(const char * filename)
     {
       char * msg;
       if (asprintf(&msg,
-                   "Abundance annotations not found for %d sequences, "
-                   "starting on line %u.\n"
-                   "Fasta headers must end with abundance annotations "
-                   "(_INT or ;size=INT)\n"
-                   "Abundance annotations can be produced by "
-                   "dereplicating the sequences\n",
+                   "Abundance annotations not found for %d sequences, starting on line %u.\n"
+                   "Fasta headers must end with abundance annotations (_INT or ;size=INT).\n"
+                   "The -z option must be used if the abundance annotation is in the latter format.\n"
+                   "Abundance annotations can be produced by dereplicating the sequences.\n",
                    missingabundance,
                    missingabundance_lineno) == -1)
         fatal("Out of memory");
diff --git a/src/derep.cc b/src/derep.cc
index 1114e278..7bfd69be 100644
--- a/src/derep.cc
+++ b/src/derep.cc
@@ -1,5 +1,7 @@
 /*
-    Copyright (C) 2014-2015 Torbjorn Rognes
+    SWARM
+
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
diff --git a/src/matrix.cc b/src/matrix.cc
index 558d7141..820e90ee 100644
--- a/src/matrix.cc
+++ b/src/matrix.cc
@@ -1,7 +1,7 @@
 /*
     SWARM
 
-    Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
diff --git a/src/nw.cc b/src/nw.cc
index 1acd2eca..585e64b6 100644
--- a/src/nw.cc
+++ b/src/nw.cc
@@ -1,7 +1,7 @@
 /*
     SWARM
 
-    Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
diff --git a/src/qgram.cc b/src/qgram.cc
index ddedcffe..496b7f40 100644
--- a/src/qgram.cc
+++ b/src/qgram.cc
@@ -1,7 +1,7 @@
 /*
     SWARM
 
-    Copyright (C) 2012-2014 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
diff --git a/src/scan.cc b/src/scan.cc
index ea8e1839..db15e544 100644
--- a/src/scan.cc
+++ b/src/scan.cc
@@ -1,7 +1,7 @@
 /*
     SWARM
 
-    Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
diff --git a/src/search16.cc b/src/search16.cc
index 174ba22d..0129a8e3 100644
--- a/src/search16.cc
+++ b/src/search16.cc
@@ -1,7 +1,7 @@
 /*
     SWARM
 
-    Copyright (C) 2012-2014 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
diff --git a/src/search8.cc b/src/search8.cc
index 4d3f13da..e022940c 100644
--- a/src/search8.cc
+++ b/src/search8.cc
@@ -1,7 +1,7 @@
 /*
     SWARM
 
-    Copyright (C) 2012-2014 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
diff --git a/src/ssse3.cc b/src/ssse3.cc
index 3c593565..03fb0df8 100644
--- a/src/ssse3.cc
+++ b/src/ssse3.cc
@@ -1,7 +1,7 @@
 /*
     SWARM
 
-    Copyright (C) 2012-2014 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
diff --git a/src/swarm.cc b/src/swarm.cc
index 31ed2566..3e822f76 100644
--- a/src/swarm.cc
+++ b/src/swarm.cc
@@ -1,7 +1,7 @@
 /*
     SWARM
 
-    Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
@@ -189,30 +189,36 @@ void args_usage()
   /*               01234567890123456789012345678901234567890123456789012345678901234567890123456789 */
 
   fprintf(stderr, "Usage: swarm [OPTIONS] [filename]\n");
-  fprintf(stderr, "  -b, --boundary INTEGER              min mass of large OTU for fastidious (3)\n");
-  fprintf(stderr, "  -c, --ceiling INTEGER               max memory in MB used for fastidious\n");
-  fprintf(stderr, "  -d, --differences INTEGER           resolution (1)\n");
-  fprintf(stderr, "  -f, --fastidious                    link nearby low-abundance swarms\n");
-  fprintf(stderr, "  -h, --help                          display this help and exit\n");
-  fprintf(stderr, "  -n, --no-otu-breaking               never break OTUs\n");
-  fprintf(stderr, "  -t, --threads INTEGER               number of threads to use (1)\n");
-  fprintf(stderr, "  -v, --version                       display version information and exit\n");
-  fprintf(stderr, "  -y, --bloom-bits INTEGER            bits used per Bloom filter entry (16)\n");
+  fprintf(stderr, "\n");
+  fprintf(stderr, "General options:\n");
+  fprintf(stderr, " -h, --help                          display this help and exit\n");
+  fprintf(stderr, " -t, --threads INTEGER               number of threads to use (1)\n");
+  fprintf(stderr, " -v, --version                       display version information and exit\n");
+  fprintf(stderr, "\n");
+  fprintf(stderr, "Clustering options:\n");
+  fprintf(stderr, " -b, --boundary INTEGER              min mass of large OTU for fastidious (3)\n");
+  fprintf(stderr, " -c, --ceiling INTEGER               max memory in MB used for fastidious\n");
+  fprintf(stderr, " -d, --differences INTEGER           resolution (1)\n");
+  fprintf(stderr, " -f, --fastidious                    link nearby low-abundance swarms\n");
+  fprintf(stderr, " -n, --no-otu-breaking               never break OTUs\n");
+  fprintf(stderr, " -y, --bloom-bits INTEGER            bits used per Bloom filter entry (16)\n");
+  fprintf(stderr, "\n");
   fprintf(stderr, "Input/output options:\n");
-  fprintf(stderr, "  -a, --append-abundance INTEGER      value to use when abundance is missing\n");  
-  fprintf(stderr, "  -i, --internal-structure FILENAME   write internal swarm structure to file\n");
-  fprintf(stderr, "  -l, --log FILENAME                  log to file, not to stderr\n");  
-  fprintf(stderr, "  -o, --output-file FILENAME          output result filename (stdout)\n");
-  fprintf(stderr, "  -r, --mothur                        output in mothur list file format\n");
-  fprintf(stderr, "  -s, --statistics-file FILENAME      dump swarm statistics to file\n");
-  fprintf(stderr, "  -u, --uclust-file FILENAME          output in UCLUST-like format to file\n");
-  fprintf(stderr, "  -w, --seeds FILENAME                write seed seqs with abundances to FASTA\n");
-  fprintf(stderr, "  -z, --usearch-abundance             abundance annotation in usearch style\n");
+  fprintf(stderr, " -a, --append-abundance INTEGER      value to use when abundance is missing\n");
+  fprintf(stderr, " -i, --internal-structure FILENAME   write internal swarm structure to file\n");
+  fprintf(stderr, " -l, --log FILENAME                  log to file, not to stderr\n");
+  fprintf(stderr, " -o, --output-file FILENAME          output result filename (stdout)\n");
+  fprintf(stderr, " -r, --mothur                        output in mothur list file format\n");
+  fprintf(stderr, " -s, --statistics-file FILENAME      dump OTU statistics to file\n");
+  fprintf(stderr, " -u, --uclust-file FILENAME          output in UCLUST-like format to file\n");
+  fprintf(stderr, " -w, --seeds FILENAME                write seed seqs with abundances to FASTA\n");
+  fprintf(stderr, " -z, --usearch-abundance             abundance annotation in usearch style\n");
+  fprintf(stderr, "\n");
   fprintf(stderr, "Pairwise alignment advanced options:\n");
-  fprintf(stderr, "  -m, --match-reward INTEGER          reward for nucleotide match (5)\n");
-  fprintf(stderr, "  -p, --mismatch-penalty INTEGER      penalty for nucleotide mismatch (4)\n");
-  fprintf(stderr, "  -g, --gap-opening-penalty INTEGER   gap open penalty (12)\n");
-  fprintf(stderr, "  -e, --gap-extension-penalty INTEGER gap extension penalty (4)\n");
+  fprintf(stderr, " -m, --match-reward INTEGER          reward for nucleotide match (5)\n");
+  fprintf(stderr, " -p, --mismatch-penalty INTEGER      penalty for nucleotide mismatch (4)\n");
+  fprintf(stderr, " -g, --gap-opening-penalty INTEGER   gap open penalty (12)\n");
+  fprintf(stderr, " -e, --gap-extension-penalty INTEGER gap extension penalty (4)\n");
   fprintf(stderr, "\n");
   fprintf(stderr, "See 'man swarm' for more details.\n");
 }
@@ -220,13 +226,17 @@ void args_usage()
 void show_header()
 {
   char title[] = "Swarm " SWARM_VERSION;
-  char ref[] = "Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe";
+  char ref[] = "Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe";
   char url[] = "https://github.com/torognes/swarm";
   fprintf(logfile, "%s [%s %s]\n%s\n%s\n\n",
           title, __DATE__, __TIME__, ref, url);
-  fprintf(logfile, "Please cite: Mahe F, Rognes T, Quince C, de Vargas C, Dunthorn M (2014)\n");
-  fprintf(logfile, "Swarm: robust and fast clustering method for amplicon-based studies.\n");
-  fprintf(logfile, "PeerJ 2:e593 https://dx.doi.org/10.7717/peerj.593\n");
+  fprintf(logfile, "Mahe F, Rognes T, Quince C, de Vargas C, Dunthorn M (2014)\n");
+  fprintf(logfile, "Swarm: robust and fast clustering method for amplicon-based studies\n");
+  fprintf(logfile, "PeerJ 2:e593 https://doi.org/10.7717/peerj.593\n");
+  fprintf(logfile, "\n");
+  fprintf(logfile, "Mahe F, Rognes T, Quince C, de Vargas C, Dunthorn M (2015)\n");
+  fprintf(logfile, "Swarm v2: highly-scalable and high-resolution amplicon clustering\n");
+  fprintf(logfile, "PeerJ 3:e1420 https://doi.org/10.7717/peerj.1420\n");
   fprintf(logfile, "\n");
 }
 
@@ -304,7 +314,7 @@ void args_init(int argc, char **argv)
       /* help */
       show_header();
       args_usage();
-      exit(1);
+      exit(0);
       break;
 
     case 'o':
@@ -320,7 +330,7 @@ void args_init(int argc, char **argv)
     case 'v':
       /* version */
       show_header();
-      exit(1);
+      exit(0);
       break;
 
     case 'm':
diff --git a/src/swarm.h b/src/swarm.h
index fe705d01..2137e91a 100644
--- a/src/swarm.h
+++ b/src/swarm.h
@@ -1,7 +1,7 @@
 /*
     SWARM
 
-    Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
@@ -52,7 +52,7 @@
 #define LINE_MAX 2048
 #endif
 
-#define SWARM_VERSION "2.1.6"
+#define SWARM_VERSION "2.1.7"
 #define WIDTH 32
 #define WIDTH_SHIFT 5
 #define BLOCKWIDTH 32
diff --git a/src/threads.h b/src/threads.h
index ebae3cbd..a7d475f0 100644
--- a/src/threads.h
+++ b/src/threads.h
@@ -1,7 +1,7 @@
 /*
     SWARM
 
-    Copyright (C) 2012-2015 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
diff --git a/src/util.cc b/src/util.cc
index 3a2e022a..c68667c4 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -1,7 +1,7 @@
 /*
     SWARM
 
-    Copyright (C) 2012-2014 Torbjorn Rognes and Frederic Mahe
+    Copyright (C) 2012-2016 Torbjorn Rognes and Frederic Mahe
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as
@@ -74,12 +74,13 @@ long gcd(long a, long b)
 
 void fatal(const char * msg)
 {
-  fprintf(stderr, "Error: %s\n", msg);
+  fprintf(stderr, "\nError: %s\n", msg);
   exit(1);
 }
 
 void fatal(const char * format, const char * message)
 {
+  fprintf(stderr, "\n");
   fprintf(stderr, format, message);
   fprintf(stderr, "\n");
   exit(1);