diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index 57ba6779feb1d2f30139d7727ecbe53dd3f0572e..7fcfa5649bc8890a4f099120d61d51bd4c2269fc 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,10 @@
+2009-07-20  Jerry Quinn  <jlquinn@optonline.net>
+
+	PR regression/40800
+	* configure.ac: Use = instead of == for testing
+	ENABLE_BUILD_WITH_CXX.
+	* configure: Rebuild.
+
 2009-07-17  Jerry Quinn  <jlquinn@optonline.net>
 
 	* directives.c (do_linemarker, do_line): Use CPP_STRING for
diff --git a/libcpp/configure b/libcpp/configure
index 35fb663bf8761d9888fa0d8cc167624446ba4a59..d622993cfe31d40a3b1a03e28907e5b6fc560b97 100755
--- a/libcpp/configure
+++ b/libcpp/configure
@@ -3342,7 +3342,7 @@ DEPDIR="${am__leading_dot}deps"
           ac_config_commands="$ac_config_commands depdir"
 
 
-if test "$ENABLE_BUILD_WITH_CXX" == "no"; then
+if test "$ENABLE_BUILD_WITH_CXX" = "no"; then
 depcc="$CC"   am_compiler_list=
 
 am_depcomp=$ac_aux_dir/depcomp
@@ -3674,7 +3674,7 @@ fi
 # AC_CHECK_HEADERS is repeated to work around apparent autoconf 2.59 bug.  If
 # AC_CHECK_HEADERS comes after the if clause, the last AC_LANG call gets used,
 # no matter which branch is taken.
-if test "$ENABLE_BUILD_WITH_CXX" == "no"; then
+if test "$ENABLE_BUILD_WITH_CXX" = "no"; then
    ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
diff --git a/libcpp/configure.ac b/libcpp/configure.ac
index a3ab8f551c370a6d81875bf4da2e8ecf2b12f2f8..6c397a98da26422da18c455640cd3a126506c28f 100644
--- a/libcpp/configure.ac
+++ b/libcpp/configure.ac
@@ -42,7 +42,7 @@ ACX_PROG_CC_WARNINGS_ARE_ERRORS([manual])
 
 # Dependency checking.
 ZW_CREATE_DEPDIR
-if test "$ENABLE_BUILD_WITH_CXX" == "no"; then
+if test "$ENABLE_BUILD_WITH_CXX" = "no"; then
 ZW_PROG_COMPILER_DEPENDENCIES([CC])
 else
 ZW_PROG_COMPILER_DEPENDENCIES([CXX])
@@ -55,7 +55,7 @@ ACX_HEADER_STRING
 # AC_CHECK_HEADERS is repeated to work around apparent autoconf 2.59 bug.  If
 # AC_CHECK_HEADERS comes after the if clause, the last AC_LANG call gets used,
 # no matter which branch is taken.
-if test "$ENABLE_BUILD_WITH_CXX" == "no"; then
+if test "$ENABLE_BUILD_WITH_CXX" = "no"; then
    AC_LANG(C)
    AC_CHECK_HEADERS(locale.h fcntl.h limits.h stddef.h \
 	stdlib.h strings.h string.h sys/file.h unistd.h)