diff --git a/exec.c b/exec.c
index f2e66f3..122e6e5 100644
--- a/exec.c
+++ b/exec.c
@@ -796,7 +796,7 @@
             iotlb |= PHYS_SECTION_ROM;
         }
     } else {
-        iotlb = section - address_space_memory.dispatch->map.sections;
+        iotlb = section - section->address_space->dispatch->map.sections;
         iotlb += xlat;
     }