diff --git a/configure.ac b/configure.ac
index 225c372158..a67ff0031c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1574,7 +1574,7 @@ AC_SUBST(OUR_DISABLED_INSTALL_MODS)
 AC_SUBST(OUR_DISABLED_UNINSTALL_MODS)
 AC_SUBST(AM_MAKEFLAGS)
 
-ac_configure_args="$ac_configure_args CONFIGURE_CFLAGS='$CFLAGS' CONFIGURE_CXXFLAGS='$CXXFLAGS' CONFIGURE_LDFLAGS='$LDFLAGS' "
+ac_configure_args="$ac_configure_args CONFIGURE_CFLAGS='$CFLAGS $CPPFLAGS' CONFIGURE_CXXFLAGS='$CXXFLAGS $CPPFLAGS' CONFIGURE_LDFLAGS='$LDFLAGS' "
 
 #	--prefix='$prefix' --exec_prefix='$exec_prefix' --libdir='$libdir' --libexecdir='$libexecdir' --bindir='$bindir' --sbindir='$sbindir' \
 #	--localstatedir='$localstatedir' --datadir='$datadir'"