diff --git a/orao/cpu.py b/orao/cpu.py
index 3bb05bb..d9dba41 100755
--- a/orao/cpu.py
+++ b/orao/cpu.py
@@ -103,7 +103,7 @@ class CPU(object):
         self.memory[addr] = val & 0xFF
 
         for listener in self.store_mem_listeners:
-            listener(addr, val)
+            listener(addr, val, self)
 
     def stack_push(self, value):
         self.store_byte(256 + self.sp, value & 0xFF)
diff --git a/orao/video.py b/orao/video.py
index f7126ad..6bedc73 100644
--- a/orao/video.py
+++ b/orao/video.py
@@ -4,7 +4,7 @@ terminal = pygame.Surface((256, 256), pygame.SRCALPHA, depth=32)
 terminal.fill((255, 255, 255))
 alphaarray = pygame.surfarray.pixels_alpha(terminal)
 
-def mem_listener(addr, val):
+def mem_listener(addr, val, cpu):
 	if 0x6000 <= addr <= 0x7FFF:  # Video RAM
 		y, x = divmod((addr - 0x6000) * 8, 256)
 		for i in range(8):