diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 543cd7f759b..08e5395495c 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2004-01-24  Mark Kettenis  <kettenis@gnu.org>
+
+	* sparcnbsd-tdep.c (GDB_OSABI_NETBSD_CORE): Define, based on the
+	value of GDB_OSABI_DEFAULT.
+	(sparcnbsd_core_osabi_sniffer): Return GDB_OSABI_NETBSD_CORE
+	instead of GDB_OSABI_NETBSD_AOUT.
+
 2004-01-24  Nick Roberts  <nick@nick.uklinux.net>
 
 	* mi/mi-cmd-stack.c, mi/mi-cmd-var.c, mi/mi-cmds.h: Update
diff --git a/gdb/sparcnbsd-tdep.c b/gdb/sparcnbsd-tdep.c
index 2547405ac55..631697c1799 100644
--- a/gdb/sparcnbsd-tdep.c
+++ b/gdb/sparcnbsd-tdep.c
@@ -284,11 +284,24 @@ sparcnbsd_aout_osabi_sniffer (bfd *abfd)
   return GDB_OSABI_UNKNOWN;
 }
 
+/* OpenBSD uses the traditional NetBSD core file format, even for
+   ports that use ELF.  Therefore, if the default OS ABI is OpenBSD
+   ELF, we return that instead of NetBSD a.out.  This is mainly for
+   the benfit of OpenBSD/sparc64, which inherits the sniffer below
+   since we include this file for an OpenBSD/sparc64 target.  For
+   OpenBSD/sparc, the NetBSD a.out OS ABI is probably similar enough
+   to both the OpenBSD a.out and the OpenBSD ELF OS ABI.  */
+#if defined (GDB_OSABI_DEFAULT) && (GDB_OSABI_DEFAULT == GDB_OSABI_OPENBSD_ELF)
+#define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF
+#else
+#define GDB_OSABI_NETBSD_CORE GDB_OSABI_NETBSD_AOUT
+#endif
+
 static enum gdb_osabi
 sparcnbsd_core_osabi_sniffer (bfd *abfd)
 {
   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
-    return GDB_OSABI_NETBSD_AOUT;
+    return GDB_OSABI_NETBSD_CORE;
 
   return GDB_OSABI_UNKNOWN;
 }