#if !(defined __SOMETHING_MORE_IMPORTANT)
# warn Be careful...
#elif !(defined __SOMETHING_REALLY_REALLY_IMPORTANT)
-# error Nup, can't go on /* ' /* stupid font-lock-mode */
+# error "Nup, can't go on" /* ' /* stupid font-lock-mode */
#else /* defined __SOMETHING_MORE_IMPORTANT && defined __SOMETHING_REALLY_REALLY_IMPORTANT */
# define EVERYTHING_IS_OK
#endif