diff --git a/Makefile b/Makefile
index 0c0a9676e..ef9b5a9a4 100644
--- a/Makefile
+++ b/Makefile
@@ -158,8 +158,8 @@ LIBHTS_SOVERSION = 3
 # is not strictly necessary and should be removed the next time
 # LIBHTS_SOVERSION is bumped (see #1144 and
 # https://developer.apple.com/library/archive/documentation/DeveloperTools/Conceptual/DynamicLibraries/100-Articles/DynamicLibraryDesignGuidelines.html#//apple_ref/doc/uid/TP40002013-SW23)
-MACH_O_COMPATIBILITY_VERSION = 3.1.20
-MACH_O_CURRENT_VERSION = 3.1.20
+MACH_O_COMPATIBILITY_VERSION = 3.1.21
+MACH_O_CURRENT_VERSION = 3.1.21
 
 # Force version.h to be remade if $(PACKAGE_VERSION) has changed.
 version.h: $(if $(wildcard version.h),$(if $(findstring "$(PACKAGE_VERSION)",$(shell cat version.h)),,force))
diff --git a/NEWS b/NEWS
index 4a573d91d..f18131df9 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,9 @@
 Noteworthy changes in release a.b
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
+Noteworthy changes in release 1.21 (12th September 2024)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
 The primary user-visible changes in this release are updates to the
 annot-tsv tool and some speed improvements.  Full details of other
 changes and bugs fixed are below.
diff --git a/annot-tsv.1 b/annot-tsv.1
index fcdec29aa..3a6034b11 100644
--- a/annot-tsv.1
+++ b/annot-tsv.1
@@ -1,5 +1,5 @@
 '\" t
-.TH annot-tsv 1 "15 April 2024" "htslib-1.20" "Bioinformatics tools"
+.TH annot-tsv 1 "12 September 2024" "htslib-1.21" "Bioinformatics tools"
 .\"
 .\" Copyright (C) 2015, 2017-2018, 2023-2024 Genome Research Ltd.
 .\"
diff --git a/bgzip.1 b/bgzip.1
index fe4225b43..1e115d044 100644
--- a/bgzip.1
+++ b/bgzip.1
@@ -1,4 +1,4 @@
-.TH bgzip 1 "15 April 2024" "htslib-1.20" "Bioinformatics tools"
+.TH bgzip 1 "12 September 2024" "htslib-1.21" "Bioinformatics tools"
 .SH NAME
 .PP
 bgzip \- Block compression/decompression utility
diff --git a/htsfile.1 b/htsfile.1
index 89a2fe446..e22fdbcda 100644
--- a/htsfile.1
+++ b/htsfile.1
@@ -1,4 +1,4 @@
-.TH htsfile 1 "15 April 2024" "htslib-1.20" "Bioinformatics tools"
+.TH htsfile 1 "12 September 2024" "htslib-1.21" "Bioinformatics tools"
 .SH NAME
 htsfile \- identify high-throughput sequencing data files
 .\"
diff --git a/htslib-s3-plugin.7 b/htslib-s3-plugin.7
index 3bd868c71..44de65771 100644
--- a/htslib-s3-plugin.7
+++ b/htslib-s3-plugin.7
@@ -1,4 +1,4 @@
-.TH htslib-s3-plugin 7 "15 April 2024" "htslib-1.20" "Bioinformatics tools"
+.TH htslib-s3-plugin 7 "12 September 2024" "htslib-1.21" "Bioinformatics tools"
 .SH NAME
 htslib-s3-plugin \- htslib AWS S3 plugin
 .\"
diff --git a/htslib.map b/htslib.map
index e342f55b5..52ad738bb 100644
--- a/htslib.map
+++ b/htslib.map
@@ -640,3 +640,13 @@ HTSLIB_1.18 {
 HTSLIB_1.20 {
     tbx_conf_gaf;
 } HTSLIB_1.18;
+
+HTSLIB_1.21 {
+    cram_container_get_coords;
+    cram_container_num2offset;
+    cram_container_offset2num;
+    cram_filter_container;
+    cram_index_extents;
+    cram_num_containers;
+    cram_num_containers_between;
+} HTSLIB_1.20;
diff --git a/htslib/hts.h b/htslib/hts.h
index 870ea4532..08bf71c2c 100644
--- a/htslib/hts.h
+++ b/htslib/hts.h
@@ -489,7 +489,7 @@ const char *hts_version(void);
 // Immediately after release, bump ZZ to 90 to distinguish in-development
 // Git repository builds from the release; you may wish to increment this
 // further when significant features are merged.
-#define HTS_VERSION 102090
+#define HTS_VERSION 102190
 
 /*! @abstract Introspection on the features enabled in htslib
  *
diff --git a/tabix.1 b/tabix.1
index 9bf1d6891..f0dc7b519 100644
--- a/tabix.1
+++ b/tabix.1
@@ -1,4 +1,4 @@
-.TH tabix 1 "15 April 2024" "htslib-1.20" "Bioinformatics tools"
+.TH tabix 1 "12 September 2024" "htslib-1.21" "Bioinformatics tools"
 .SH NAME
 .PP
 tabix \- Generic indexer for TAB-delimited genome position files
diff --git a/version.sh b/version.sh
index 98ae48ec0..f35234c2d 100755
--- a/version.sh
+++ b/version.sh
@@ -24,7 +24,7 @@
 # DEALINGS IN THE SOFTWARE.
 
 # Master version, for use in tarballs or non-git source copies
-VERSION=1.20
+VERSION=1.21
 
 # If we have a git clone, then check against the current tag
 srcdir=${0%/version.sh}