diff --git a/src/optiondefs.h b/src/optiondefs.h
index 42f355c..782e4ef 100644
--- a/src/optiondefs.h
+++ b/src/optiondefs.h
@@ -3033,7 +3033,7 @@
     {NULL, NULL, 0, NULL, PV_NONE, {NULL, NULL} SCTX_INIT}
 };
 
-#define OPTION_COUNT (sizeof(options) / sizeof(struct vimoption))
+#define OPTION_COUNT ARRAY_LENGTH(options)
 
 // The following is needed to make the gen_opt_test.vim script work.
 // {"