diff --git a/core/Makefile b/core/Makefile
index 82cd784dc..9e001f30f 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -1063,6 +1063,9 @@ endif
 	$(hide) echo "tool_extensions=$(tool_extensions)" >> $(zip_root)/META/misc_info.txt
 ifdef mkyaffs2_extra_flags
 	$(hide) echo "mkyaffs2_extra_flags=$(mkyaffs2_extra_flags)" >> $(zip_root)/META/misc_info.txt
+endif
+ifdef INTERNAL_USERIMAGES_SPARSE_EXT_FLAG
+	$(hide) echo "extfs_sparse_flag=$(INTERNAL_USERIMAGES_SPARSE_EXT_FLAG)" >> $(zip_root)/META/misc_info.txt
 endif
 	@# Zip everything up, preserving symlinks
 	$(hide) (cd $(zip_root) && zip -qry ../$(notdir $@) .)
diff --git a/tools/releasetools/img_from_target_files b/tools/releasetools/img_from_target_files
index 488226fe4..793f7acd6 100755
--- a/tools/releasetools/img_from_target_files
+++ b/tools/releasetools/img_from_target_files
@@ -63,9 +63,11 @@ def AddUserdata(output_zip):
   build_command = []
   fstab = OPTIONS.info_dict["fstab"]
   if fstab and fstab["/data"].fs_type.startswith("ext"):
-    build_command = ["mkuserimg.sh",
-                     user_dir, img.name,
-                     fstab["/data"].fs_type, "data"]
+    build_command = ["mkuserimg.sh"]
+    if "extfs_sparse_flag" in OPTIONS.info_dict:
+      build_command.append(OPTIONS.info_dict["extfs_sparse_flag"])
+    build_command.extend([user_dir, img.name,
+                     fstab["/data"].fs_type, "data"])
     if "userdata_size" in OPTIONS.info_dict:
       build_command.append(str(OPTIONS.info_dict["userdata_size"]))
   else:
@@ -112,9 +114,12 @@ def AddSystem(output_zip):
   build_command = []
   fstab = OPTIONS.info_dict["fstab"]
   if fstab and fstab["/system"].fs_type.startswith("ext"):
-    build_command = ["mkuserimg.sh",
-                     os.path.join(OPTIONS.input_tmp, "system"), img.name,
-                     fstab["/system"].fs_type, "system"]
+
+    build_command = ["mkuserimg.sh"]
+    if "extfs_sparse_flag" in OPTIONS.info_dict:
+      build_command.append(OPTIONS.info_dict["extfs_sparse_flag"])
+    build_command.extend([os.path.join(OPTIONS.input_tmp, "system"), img.name,
+                     fstab["/system"].fs_type, "system"])
     if "system_size" in OPTIONS.info_dict:
       build_command.append(str(OPTIONS.info_dict["system_size"]))
   else: