diff --git a/man/swarm.1 b/man/swarm.1
index fb739345..b3d0a071 100644
--- a/man/swarm.1
+++ b/man/swarm.1
@@ -1,5 +1,5 @@
 .\" ============================================================================
-.TH swarm 1 "September 28, 2022" "version 3.1.1" "USER COMMANDS"
+.TH swarm 1 "September 29, 2022" "version 3.1.1" "USER COMMANDS"
 .\" ============================================================================
 .SH NAME
 swarm \(em find clusters of nearly-identical nucleotide amplicons
@@ -527,7 +527,7 @@ New features and important modifications of \fBswarm\fR (short lived
 or minor bug releases are not mentioned):
 .RS
 .TP
-.BR v3.1.1\~ "released September 28, 2022"
+.BR v3.1.1\~ "released September 29, 2022"
 Version 3.1.1 eliminates a risk of segmentation fault with extremely
 long sequence headers. Documentation and error messages have been
 improved, and code cleaning continued.
diff --git a/src/swarm.h b/src/swarm.h
index 40f21a57..83923ddb 100644
--- a/src/swarm.h
+++ b/src/swarm.h
@@ -104,7 +104,7 @@ static_assert(INT_MAX > INT16_MAX, "Your compiler uses very short integers.");
 
 /* constants */
 
-const std::string swarm_version {"3.1.0"};
+const std::string swarm_version {"3.1.1"};
 constexpr char sepchar {' '};
 constexpr char dash_filename {'-'};
 constexpr unsigned int opt_differences_default {1};