diff --git a/afsk/main.c b/afsk/main.c
index 9ef0397d..de583da6 100644
--- a/afsk/main.c
+++ b/afsk/main.c
@@ -454,7 +454,7 @@ return 0;
 int encodeA(uint8_t *b, int index, int val) {
     printf("Encoding A\n");
     b[index] = (val & 0xff);
-    b[index + 1] = str[index + 1] | (val >> 8);
+    b[index + 1] = b[index + 1] | (val >> 8);
     return 0;	
 }