diff --git a/uc.c b/uc.c
index 76c4eb28..a1a71366 100644
--- a/uc.c
+++ b/uc.c
@@ -1524,7 +1524,7 @@ MemoryRegion *find_memory_region(struct uc_struct *uc, uint64_t address)
 
     if (i < uc->mapped_block_count &&
         address >= uc->mapped_blocks[i]->addr &&
-        address < uc->mapped_blocks[i]->end) {
+        address <= uc->mapped_blocks[i]->end - 1) {
         return uc->mapped_blocks[i];
     }
 
@@ -1532,8 +1532,10 @@ MemoryRegion *find_memory_region(struct uc_struct *uc, uint64_t address)
 
     if (i < uc->mapped_block_count &&
         address >= uc->mapped_blocks[i]->addr &&
-        address <= uc->mapped_blocks[i]->end - 1)
+        address <= uc->mapped_blocks[i]->end - 1) {
+        uc->mapped_block_cache_index = i;
         return uc->mapped_blocks[i];
+    }
 
     // not found
     return NULL;