diff --git a/BaS_gcc/include/driver_vec.h b/BaS_gcc/include/driver_vec.h
index 9c83a6a..70f5cf9 100644
--- a/BaS_gcc/include/driver_vec.h
+++ b/BaS_gcc/include/driver_vec.h
@@ -265,9 +265,9 @@ struct pci_bios_interface
 
 struct mmu_driver_interface
 {
-    int32_t (*map_page_locked)(uint32_t address, uint32_t length, int asid);
-    int32_t (*unlock_page)(uint32_t address, uint32_t length, int asid);
-    int32_t (*report_locked_pages)(uint32_t *num_itlb, uint32_t *num_dtlb);
+    uint32_t (*map_page_locked)(uint32_t address, uint32_t length, int asid);
+    uint32_t (*unlock_page)(uint32_t address, uint32_t length, int asid);
+    uint32_t (*report_locked_pages)(uint32_t *num_itlb, uint32_t *num_dtlb);
     uint32_t (*report_pagesize)(void);
 };