diff --git a/configure b/configure
index 2a8fa9a..099f867 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision: 1.371 .
+# From configure.in Revision: 1.372 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.53 for python 2.3.
 #
@@ -2999,6 +2999,20 @@
 fi
 
 
+# Check for unsupported systems
+case $ac_sys_system/$ac_sys_release in
+SunOS/4*|DYNIX/*|dgux*/*|IRIX/4*|Linux*/1*)
+   echo This system \($ac_sys_system/$ac_sys_release\) is no longer supported.
+   echo See README for details.
+   exit 1;;
+esac
+
+if test "$MINIX" = yes; then
+   echo This system \(MINIX\) is no longer supported.
+   echo Read README for details.
+   exit 1
+fi
+
 
 echo "$as_me:$LINENO: checking for --with-suffix" >&5
 echo $ECHO_N "checking for --with-suffix... $ECHO_C" >&6
@@ -10866,6 +10880,9 @@
 #define WITH_THREAD 1
 _ACEOF
 
+    echo Systems with __d6_pthread_create are not supported anymore.
+    echo See README
+    exit 1
     posix_threads=yes
     LIBS="$LIBS -lthread"
     THREADOBJ="Python/thread.o"
@@ -11733,6 +11750,8 @@
 
 echo "$as_me:$LINENO: result: $withval" >&5
 echo "${ECHO_T}$withval" >&6
+echo --with-sgi-dl is unsupported; see README
+exit 1
 
 cat >>confdefs.h <<\_ACEOF
 #define WITH_SGI_DL 1
@@ -11762,6 +11781,8 @@
 
 echo "$as_me:$LINENO: result: $withval" >&5
 echo "${ECHO_T}$withval" >&6
+echo --with-dl-dld is unsupported; see README
+exit 1
 
 cat >>confdefs.h <<\_ACEOF
 #define WITH_DL_DLD 1