diff --git a/gdbsupport/osabi.def b/gdbsupport/osabi.def
index 637da26..417c670 100644
--- a/gdbsupport/osabi.def
+++ b/gdbsupport/osabi.def
@@ -37,6 +37,7 @@ GDB_OSABI_DEF (NONE, "none", nullptr)
 GDB_OSABI_DEF (SVR4, "SVR4", nullptr)
 GDB_OSABI_DEF (HURD, "GNU/Hurd", nullptr)
 GDB_OSABI_DEF (SOLARIS, "Solaris", nullptr)
+GDB_OSABI_DEF (ILLUMOS, "illumos", "solaris[2-9]\.[0-9][0-9]")
 GDB_OSABI_DEF (LINUX, "GNU/Linux", "linux(-gnu[^-]*)?")
 GDB_OSABI_DEF (FREEBSD, "FreeBSD", nullptr)
 GDB_OSABI_DEF (NETBSD, "NetBSD", nullptr)