Index: share/man/man5/elf.5
===================================================================
--- share/man/man5/elf.5
+++ share/man/man5/elf.5
@@ -1103,6 +1103,10 @@
 .Dv ELFCOMPRESS_ZLIB
 indicates that the data is compressed using
 .Xr zlib 3 .
+A value of
+.Dv ELFCOMPRESS_ZSTD
+indicates that the data is compressed using
+Zstandard.
 .It Dv ch_size
 The size, in bytes, of the uncompressed section data.
 This corresponds to the
Index: sys/sys/elf_common.h
===================================================================
--- sys/sys/elf_common.h
+++ sys/sys/elf_common.h
@@ -944,6 +944,7 @@
 
 /* Values for ch_type (compressed section headers). */
 #define	ELFCOMPRESS_ZLIB	1	/* ZLIB/DEFLATE */
+#define	ELFCOMPRESS_ZSTD	2	/* Zstandard */
 #define	ELFCOMPRESS_LOOS	0x60000000	/* OS-specific */
 #define	ELFCOMPRESS_HIOS	0x6fffffff
 #define	ELFCOMPRESS_LOPROC	0x70000000	/* Processor-specific */