diff --git a/ext/mime_magic/mime_magic.c b/ext/mime_magic/mime_magic.c
index bdb1dab794c..86c650c699f 100644
--- a/ext/mime_magic/mime_magic.c
+++ b/ext/mime_magic/mime_magic.c
@@ -358,7 +358,7 @@ static int apprentice(void)
     fname = conf->magicfile; /* todo cwd? */
     f = fopen(fname, "rb");
     if (f == NULL) {
-		(int) conf->magic = -1;
+		*(int *)&conf->magic = -1;
 		return -1;
     }