diff --git a/source/arm11/cheat.c b/source/arm11/cheat.c
index eedf2a6..404f94e 100644
--- a/source/arm11/cheat.c
+++ b/source/arm11/cheat.c
@@ -401,7 +401,13 @@ static CodeLocation rom_fit_newsize( CodeLocation rom, int realend, int totalsiz
 
     // grow cart volumn
     else if( szrom < size || nextPow2(size) != nextPow2(szrom) )
-        *newsize = size;
+    {
+        u32 sznrom = nextPow2(size);
+        u32 start = realend - INSTR_SIZE;
+        memset( &rom[INSTR_LEN(start)], 0, sznrom-start );
+        *newsize = sznrom;
+        return rom + sznrom - ( (totalsize+0x1f) & (~0xf) );
+    }
     
     return rom + INSTR_LEN( realend );
 }