diff --git a/configure.base b/configure.base
index 1aa8ff65c3..1c1b4a134e 100644
--- a/configure.base
+++ b/configure.base
@@ -603,10 +603,10 @@ AC_CHECK_HEADER(libraw1394/raw1394.h, :, HAVE_RAW1394=no)
 dnl Check for libdv
 AC_MSG_CHECKING(libdv)
 AC_CHECK_LIB(dv, dv_init, HAVE_LIBDV=yes, HAVE_LIBDV=no, -lm $GLIB_LIBS $GLIB_CFLAGS)
-CPPFLAGS="$libdvcheck_save_CPPFLAGS"
+libdvcheck_save_CPPFLAGS="$CPPFLAGS"
 CPPFLAGS="$CPPFLAGS $GLIB_CFLAGS"
 AC_CHECK_HEADER(libdv/dv.h, :, HAVE_LIBDV=no)
-libdvcheck_save_CPPFLAGS="$CPPFLAGS"
+CPPFLAGS="$libdvcheck_save_CPPFLAGS"
 
 dnl Check for aalib
 AC_MSG_CHECKING(aalib)
@@ -641,10 +641,10 @@ if sdl-config --libs > /dev/null 2>&1; then
   AC_CHECK_LIB(SDL, SDL_Init, :, HAVE_LIBSDL=no, $SDL_LIBS)
   dnl AC_CHECK_HEADER uses CPPFLAGS, but not CFLAGS.
   dnl Assume only suitable flags result from artsc-config --cflags
-  CPPFLAGS="$sdlcheck_save_CPPFLAGS"
+  sdlcheck_save_CPPFLAGS="$CPPFLAGS"
   CPPFLAGS="$CPPFLAGS $SDL_CFLAGS"
   AC_CHECK_HEADER(SDL.h, :, HAVE_LIBSDL=no)
-  sdlcheck_save_CPPFLAGS="$CPPFLAGS"
+  CPPFLAGS="$sdlcheck_save_CPPFLAGS"
   AC_CHECK_LIB(SDL, SDL_CreateYUVOverlay, :, HAVE_LIBSDL=no, $SDL_LIBS)
 else
   AC_MSG_RESULT(not found)