--- a/configure.ac
+++ b/configure.ac
@@ -66,14 +66,14 @@ AM_CONDITIONAL([SUPPORTS_GNU_PLUS_PLUS_1
 
 # force us into gnu++98 mode if necessary
 # If gnu++11 and gnu++98 then
-#   If no unit tests, force to gnu++98
+#   If no unit tests, force to gnu++11
 #   If unittests and cppunit < 1.14.0, force to gnu++98
 #   Else turn off deprecation messages for std::auto_ptr and run gnu++11
 require_gnu_plus_plus_11="no"
 AS_IF([test "x$ac_cv_gnu_plus_plus_11" = xyes],
       [AS_IF([test "x$ac_cv_gnu_plus_plus_98" = xyes],
              [AS_IF([test "x$enable_unittests" = xno],
-                    [CXXFLAGS="$CXXFLAGS -std=gnu++98"],
+                    [require_gnu_plus_plus_11="yes"],
                     [PKG_CHECK_MODULES([CPPUNIT1], [cppunit < 1.14.0],
                                        [CXXFLAGS="$CXXFLAGS -std=gnu++98"],
                                        [PKG_CHECK_MODULES([CPPUNIT2], [cppunit >= 1.14.0],