diff --git a/tools/releasetools/add_img_to_target_files.py b/tools/releasetools/add_img_to_target_files.py
index 10aecf9..4af10ca 100755
--- a/tools/releasetools/add_img_to_target_files.py
+++ b/tools/releasetools/add_img_to_target_files.py
@@ -113,22 +113,33 @@
 
   Returns:
     (which, care_map_ranges): care_map_ranges is the raw string of the care_map
-    RangeSet.
+    RangeSet; or an empty list.
   """
   assert which in common.PARTITIONS_WITH_CARE_MAP
 
-  simg = sparse_img.SparseImage(imgname)
-  care_map_ranges = simg.care_map
-  size_key = which + "_image_size"
-  image_size = OPTIONS.info_dict.get(size_key)
-  if image_size:
-    # excludes the verity metadata blocks of the given image. When AVB is enabled,
-    # this size is the max image size returned by the AVB tool
-    image_blocks = int(image_size) / 4096 - 1
-    assert image_blocks > 0, "blocks for {} must be positive".format(which)
-    care_map_ranges = care_map_ranges.intersect(
+  # which + "_image_size" contains the size that the actual filesystem image
+  # resides in, which is all that needs to be verified. The additional blocks in
+  # the image file contain verity metadata, by reading which would trigger
+  # invalid reads.
+  image_size = OPTIONS.info_dict.get(which + "_image_size")
+  if not image_size:
+    return []
+
+  image_blocks = int(image_size) / 4096 - 1
+  assert image_blocks > 0, "blocks for {} must be positive".format(which)
+
+  # For sparse images, we will only check the blocks that are listed in the care
+  # map, i.e. the ones with meaningful data.
+  if "extfs_sparse_flag" in OPTIONS.info_dict:
+    simg = sparse_img.SparseImage(imgname)
+    care_map_ranges = simg.care_map.intersect(
         rangelib.RangeSet("0-{}".format(image_blocks)))
 
+  # Otherwise for non-sparse images, we read all the blocks in the filesystem
+  # image.
+  else:
+    care_map_ranges = rangelib.RangeSet("0-{}".format(image_blocks))
+
   return [which, care_map_ranges.to_string_raw()]
 
 
diff --git a/tools/releasetools/test_add_img_to_target_files.py b/tools/releasetools/test_add_img_to_target_files.py
index 013ade6..422262c 100644
--- a/tools/releasetools/test_add_img_to_target_files.py
+++ b/tools/releasetools/test_add_img_to_target_files.py
@@ -123,6 +123,9 @@
   def _test_AddCareMapForAbOta():
     """Helper function to set up the test for test_AddCareMapForAbOta()."""
     OPTIONS.info_dict = {
+        'extfs_sparse_flag' : '-s',
+        'system_image_size' : 65536,
+        'vendor_image_size' : 40960,
         'system_verity_block_device': '/dev/block/system',
         'vendor_verity_block_device': '/dev/block/vendor',
         'system.build.prop': {
@@ -131,7 +134,7 @@
         },
         'vendor.build.prop': {
             'ro.vendor.build.fingerprint': 'google/sailfish/678:user/dev-keys',
-        }
+        },
     }
 
     # Prepare the META/ folder.
@@ -142,9 +145,9 @@
     system_image = test_utils.construct_sparse_image([
         (0xCAC1, 6),
         (0xCAC3, 4),
-        (0xCAC1, 6)])
+        (0xCAC1, 8)])
     vendor_image = test_utils.construct_sparse_image([
-        (0xCAC2, 10)])
+        (0xCAC2, 12)])
 
     image_paths = {
         'system' : system_image,
@@ -203,6 +206,9 @@
     """Tests the case for device using AVB."""
     image_paths = self._test_AddCareMapForAbOta()
     OPTIONS.info_dict = {
+        'extfs_sparse_flag' : '-s',
+        'system_image_size' : 65536,
+        'vendor_image_size' : 40960,
         'avb_system_hashtree_enable' : 'true',
         'avb_vendor_hashtree_enable' : 'true',
         'system.build.prop': {
@@ -231,6 +237,9 @@
     """Tests the case for partitions without fingerprint."""
     image_paths = self._test_AddCareMapForAbOta()
     OPTIONS.info_dict = {
+        'extfs_sparse_flag' : '-s',
+        'system_image_size' : 65536,
+        'vendor_image_size' : 40960,
         'system_verity_block_device': '/dev/block/system',
         'vendor_verity_block_device': '/dev/block/vendor',
     }
@@ -249,6 +258,9 @@
     """Tests the case for partitions with thumbprint."""
     image_paths = self._test_AddCareMapForAbOta()
     OPTIONS.info_dict = {
+        'extfs_sparse_flag' : '-s',
+        'system_image_size' : 65536,
+        'vendor_image_size' : 40960,
         'system_verity_block_device': '/dev/block/system',
         'vendor_verity_block_device': '/dev/block/vendor',
         'system.build.prop': {
@@ -256,7 +268,7 @@
         },
         'vendor.build.prop' : {
             'ro.vendor.build.thumbprint': 'google/sailfish/456:user/dev-keys',
-        }
+        },
     }
 
     AddCareMapForAbOta(None, ['system', 'vendor'], image_paths)
@@ -370,6 +382,7 @@
         (0xCAC3, 4),
         (0xCAC1, 6)])
     OPTIONS.info_dict = {
+        'extfs_sparse_flag' : '-s',
         'system_image_size' : 53248,
     }
     name, care_map = GetCareMap('system', sparse_image)
@@ -385,6 +398,17 @@
         (0xCAC3, 4),
         (0xCAC1, 6)])
     OPTIONS.info_dict = {
+        'extfs_sparse_flag' : '-s',
         'system_image_size' : -45056,
     }
     self.assertRaises(AssertionError, GetCareMap, 'system', sparse_image)
+
+  def test_GetCareMap_nonSparseImage(self):
+    OPTIONS.info_dict = {
+        'system_image_size' : 53248,
+    }
+    # 'foo' is the image filename, which is expected to be not used by
+    # GetCareMap().
+    name, care_map = GetCareMap('system', 'foo')
+    self.assertEqual('system', name)
+    self.assertEqual(RangeSet("0-12").to_string_raw(), care_map)