diff --git a/src/py65/disassembler.py b/src/py65/disassembler.py
index 2f7451e..42f9921 100644
--- a/src/py65/disassembler.py
+++ b/src/py65/disassembler.py
@@ -80,6 +80,7 @@ class Disassembler:
 
         if addressing == 'acc':
             disasm += ' A'
+            length = 1
 
         elif addressing ==  'abs':
             address = self._mpu.WordAt(pc + 1)