diff --git a/ares/ares_getopt.c b/ares/ares_getopt.c
index 3b565a49a..177b26fea 100644
--- a/ares/ares_getopt.c
+++ b/ares/ares_getopt.c
@@ -82,7 +82,7 @@ ares_getopt(int nargc, char * const nargv[], const char *ostr)
         }
     }                                         /* option letter okay? */
     if ((optopt = (int)*place++) == (int)':' ||
-        !(oli = strchr(ostr, optopt))) {
+        (oli = strchr(ostr, optopt)) == NULL) {
         /*
          * if the user didn't specify '-' as an option,
          * assume it means EOF.