diff --git a/src/disk.c b/src/disk.c
index 03b6e7b1..c028ffe2 100644
--- a/src/disk.c
+++ b/src/disk.c
@@ -527,9 +527,10 @@ static bool save_track_data(void) {
 
 GLUE_C_READ(disk_read_write_byte)
 {
-    uint8_t value = 0xFF;
+    uint8_t value = 0x00;
     do {
         if (disk6.disk[disk6.drive].fp == NULL) {
+            ////ERRLOG_THROTTLE("OOPS, attempt to read byte from NULL image in drive (%d)", disk6.drive+1);
             break;
         }
 
diff --git a/src/test/testdisk.c b/src/test/testdisk.c
index 8b0b0c38..b36b6cb1 100644
--- a/src/test/testdisk.c
+++ b/src/test/testdisk.c
@@ -226,7 +226,7 @@ TEST test_read_null_bytes() {
     BOOT_TO_DOS();
 
     apple_ii_64k[0][WATCHPOINT_ADDR] = 0x00;
-    apple_ii_64k[0][TESTOUT_ADDR] = 0x00;
+    apple_ii_64k[0][TESTOUT_ADDR] = 0xAA;
 
     ASM_INIT();
     ASM_TEST_DISK_READ_NULL();
@@ -237,7 +237,7 @@ TEST test_read_null_bytes() {
     c_debugger_go();
 
     ASSERT(apple_ii_64k[0][WATCHPOINT_ADDR] == TEST_FINISHED);
-    ASSERT(apple_ii_64k[0][TESTOUT_ADDR]    == 0xFF);
+    ASSERT(apple_ii_64k[0][TESTOUT_ADDR]    == 0x00);
 
     PASS();
 }