Unsupport --without-universal-newlines.
diff --git a/README b/README
index abea8db..b7b53af 100644
--- a/README
+++ b/README
@@ -245,6 +245,7 @@
 - Systems defining PY_PTHREAD_D4, PY_PTHREAD_D6,
   or PY_PTHREAD_D7 in thread_pthread.h
 - Systems using --with-dl-dld
+- Systems using --without-universal-newlines
 
 Platform specific notes
 -----------------------
@@ -957,7 +958,7 @@
 	any of \r, \n or \r\n is acceptable as end-of-line character.
 	If enabled import and execfile will automatically accept any newline
 	in files. Python code can open a file with open(file, 'U') to
-	read it in universal newline mode.
+	read it in universal newline mode. THIS OPTION IS UNSUPPORTED.
 
 
 Building for multiple architectures (using the VPATH feature)
diff --git a/configure b/configure
index 20d7199..a5e51b3 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision: 1.374 .
+# From configure.in Revision: 1.375 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.53 for python 2.3.
 #
@@ -11653,7 +11653,9 @@
 if test -z "$with_universal_newlines"
 then with_universal_newlines="yes"
 fi
-if test "$with_universal_newlines" != "no"
+if test "$with_universal_newlines" = "no"
+    echo --without-universal-newlines is unsupported, see README
+    exit 1
 then
 
 cat >>confdefs.h <<\_ACEOF
diff --git a/configure.in b/configure.in
index f41b11d..c6fd6a1 100644
--- a/configure.in
+++ b/configure.in
@@ -1606,7 +1606,9 @@
 if test -z "$with_universal_newlines"
 then with_universal_newlines="yes"
 fi
-if test "$with_universal_newlines" != "no"
+if test "$with_universal_newlines" = "no"
+    echo --without-universal-newlines is unsupported, see README
+    exit 1
 then
     AC_DEFINE(WITH_UNIVERSAL_NEWLINES, 1,
       [Define if you want to read files with foreign newlines.])