diff --git a/core/droiddoc.mk b/core/droiddoc.mk
index d5ddf08..316054b 100644
--- a/core/droiddoc.mk
+++ b/core/droiddoc.mk
@@ -131,18 +131,17 @@
 $(full_target): PRIVATE_IN_CUSTOM_ASSET_DIR := $(LOCAL_DROIDDOC_CUSTOM_TEMPLATE_DIR)/$(LOCAL_DROIDDOC_CUSTOM_ASSET_DIR)
 $(full_target): PRIVATE_OUT_ASSET_DIR := $(out_dir)/$(LOCAL_DROIDDOC_ASSET_DIR)
 $(full_target): PRIVATE_OUT_CUSTOM_ASSET_DIR := $(out_dir)/$(LOCAL_DROIDDOC_CUSTOM_ASSET_DIR)
+
+html_dir_files :=
 ifneq ($(strip $(LOCAL_DROIDDOC_HTML_DIR)),)
 $(full_target): PRIVATE_DROIDDOC_HTML_DIR := -htmldir $(LOCAL_PATH)/$(LOCAL_DROIDDOC_HTML_DIR)
+html_dir_files := $(shell find $(LOCAL_PATH)/$(LOCAL_DROIDDOC_HTML_DIR) -type f)
 else
-$(full_target): PRIVATE_DROIDDOC_HTML_DIR := 
+$(full_target): PRIVATE_DROIDDOC_HTML_DIR :=
 endif
 ifneq ($(strip $(LOCAL_ADDITIONAL_HTML_DIR)),)
 $(full_target): PRIVATE_ADDITIONAL_HTML_DIR := -htmldir2 $(LOCAL_PATH)/$(LOCAL_ADDITIONAL_HTML_DIR)
-else
-$(full_target): PRIVATE_ADDITIONAL_HTML_DIR :=
-endif
-ifneq ($(strip $(LOCAL_ADDITIONAL_HTML_DIR)),)
-$(full_target): PRIVATE_ADDITIONAL_HTML_DIR := -htmldir2 $(LOCAL_PATH)/$(LOCAL_ADDITIONAL_HTML_DIR)
+html_dir_files += $(shell find $(LOCAL_PATH)/$(LOCAL_ADDITIONAL_HTML_DIR) -type f)
 else
 $(full_target): PRIVATE_ADDITIONAL_HTML_DIR :=
 endif
@@ -150,8 +149,6 @@
 # TODO: not clear if this is used any more
 $(full_target): PRIVATE_LOCAL_PATH := $(LOCAL_PATH)
 
-html_dir_files := $(shell find $(LOCAL_PATH)/$(LOCAL_DROIDDOC_HTML_DIR) -type f)
-
 $(full_target): $(full_src_files) $(droiddoc_templates) $(droiddoc) $(html_dir_files) $(full_java_lib_deps) $(LOCAL_ADDITIONAL_DEPENDENCIES)
 	@echo Docs droiddoc: $(PRIVATE_OUT_DIR)
 	$(hide) mkdir -p $(dir $@)