diff --git a/litex/soc/integration/common.py b/litex/soc/integration/common.py
index 695e56090..a5ac066ac 100644
--- a/litex/soc/integration/common.py
+++ b/litex/soc/integration/common.py
@@ -13,12 +13,11 @@ from migen import *
 # Helpers ----------------------------------------------------------------------------------------
 
 def mem_decoder(address, size=0x10000000):
-    address &= ~0x80000000
     size = 2**log2_int(size, False)
     assert (address & (size - 1)) == 0
     address >>= 2 # bytes to words aligned
     size    >>= 2 # bytes to words aligned
-    return lambda a: (a[log2_int(size):-1] == (address >> log2_int(size)))
+    return lambda a: (a[log2_int(size):] == (address >> log2_int(size)))
 
 def get_version(with_time=True):
     if with_time: