diff --git a/core/hw/mem/mem_watch.cpp b/core/hw/mem/mem_watch.cpp
index 321906f58..2d33dc541 100644
--- a/core/hw/mem/mem_watch.cpp
+++ b/core/hw/mem/mem_watch.cpp
@@ -157,7 +157,7 @@ u32 ElanRamWatcher::getMemOffset(void *p)
 		addr &= 0x1fffffff;
 		if (addr < 0x0a000000 || addr >= 0x0a000000 + ELAN_RAM_SIZE)
 			return -1;
-		addr &= ~(ELAN_RAM_SIZE - 1);
+		addr &= ELAN_RAM_SIZE - 1;
 	} else {
 		if ((u8 *)p < RAM || (u8 *)p >= &RAM[ELAN_RAM_SIZE])
 			return -1;