diff --git a/cfg/atari7800.cfg b/cfg/atari7800.cfg
index 85abc24ee..562dd3857 100644
--- a/cfg/atari7800.cfg
+++ b/cfg/atari7800.cfg
@@ -4,7 +4,7 @@
 
 SYMBOLS {
     __STACKSIZE__:        type = weak, value = $0600; # C stack
-    __CARTSIZE__:         type = weak, value = $c000;
+    __CARTSIZE__:         type = weak, value = $8000;
     __VEC_BOTTOM__:       value = $fffa, type = export;
     __VEC_SIZE__:         value = $6, type = export;
     __ENCRYPT_BOTTOM__:   value = $ff7a, type = export;
@@ -12,7 +12,7 @@ SYMBOLS {
     __MEMORY_TOP__:       value = __ENCRYPT_BOTTOM__, type = export;
     __INIT_SIZE__:        value = 69, type = export;
     __MEMORY_INIT__:      value = __MEMORY_TOP__ - __INIT_SIZE__, type = export;
-    __MEMORY_BOTTOM__:    value = $8000, type = export;
+    __MEMORY_BOTTOM__:    value = $10000 - __CARTSIZE__, type = weak;
     __FREE_ROM_SIZE__:    value = __MEMORY_INIT__ - __MEMORY_BOTTOM__, type = export;
 }