diff --git a/test/pbwalk.py b/test/pbwalk.py
index c02579f..3de2c48 100644
--- a/test/pbwalk.py
+++ b/test/pbwalk.py
@@ -50,9 +50,10 @@ def main():
 
     os.makedirs(workdir, exist_ok=True)
     dump = os.path.join(workdir, "dump.bin")
-    # The ssd1306 board's own fuses, and the same boot section with reset left
-    # on the application - the one difference that decides the refusal.
-    bricking, harmless = "ffffffdc", "ffffffdd"
+    # The ssd1306 board's own fuses, as an Atmel-ICE reads them off the part,
+    # and the same boot section with reset left on the application - the one
+    # difference that decides the refusal.
+    bricking, harmless = "fffffddc", "fffffddd"
 
     def session(fuses):
         return pbsim.Device(device_bin, elf, mcu, hz, base_hex, page, baud, dump, fuses=fuses)