diff --git a/sim/configure.ac b/sim/configure.ac
index fad5b71ee59..e9ec6e70efc 100644
--- a/sim/configure.ac
+++ b/sim/configure.ac
@@ -84,6 +84,18 @@ m4_define([SIM_TARGET], [dnl
   AM_CONDITIONAL([SIM_ENABLE_ARCH_$2], [${sim_enable_arch_$2}])
 ])
 
+case $target in
+ arm*-*-* | \
+ null)
+    if test "x$enable_obsolete" != xyes; then
+      echo "*** Configuration $targ is obsolete." >&2
+      echo "*** Specify --enable-obsolete to build it anyway." >&2
+      echo "*** Support will be REMOVED in the next major release of GDB," >&2
+      echo "*** unless a maintainer comes forward." >&2
+      exit 1
+    fi;;
+esac
+
 dnl WHEN ADDING ENTRIES TO THIS MATRIX:
 dnl Make sure that the left side always has two dashes.  Otherwise you can get
 dnl spurious matches.  Even for unambiguous cases, do this as a convention, else