diff --git a/day4.c b/day4.c
index 10b8fa8..e3ab9cc 100644
--- a/day4.c
+++ b/day4.c
@@ -148,8 +148,8 @@ line_start:
                     + (*(d - 0 + line_stride) == '@')
                     + (*(d + 1 + line_stride) == '@');
                 if (neighbors < 4) {
-                    *d = '.';
-                    result++;
+                    (*((volatile unsigned long *)&result))++;
+                    *(volatile unsigned char *)d = '.';
                     if (i > line_count-1) {
                         i = line_count;
                         l = buf + line_stride + 1;