diff --git a/core/Makefile b/core/Makefile
index ca7eba0..82cd784 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -579,8 +579,12 @@
 endif
 endif
 
+ifneq (true,$(TARGET_USERIMAGES_SPARSE_EXT_DISABLED))
+  INTERNAL_USERIMAGES_SPARSE_EXT_FLAG := -s
+endif
+
 ifeq ($(INTERNAL_USERIMAGES_USE_EXT),true)
-INTERNAL_USERIMAGES_DEPS := $(MKEXT2USERIMG) $(MAKE_EXT4FS)
+INTERNAL_USERIMAGES_DEPS := $(MKEXTUSERIMG) $(MAKE_EXT4FS)
 INTERNAL_USERIMAGES_BINARY_PATHS := $(sort $(dir $(INTERNAL_USERIMAGES_DEPS)))
 
 # $(1): src directory
@@ -591,7 +595,7 @@
 define build-userimage-ext-target
   @mkdir -p $(dir $(2))
   $(hide) PATH=$(foreach p,$(INTERNAL_USERIMAGES_BINARY_PATHS),$(p):)$(PATH) \
-	  $(MKEXT2USERIMG) $(1) $(2) $(4) $(3) $(5)
+	  $(MKEXTUSERIMG) $(INTERNAL_USERIMAGES_SPARSE_EXT_FLAG) $(1) $(2) $(4) $(3) $(5)
 endef
 else
 INTERNAL_USERIMAGES_DEPS := $(MKYAFFS2)