diff --git a/twmincrypt/Android.mk b/twmincrypt/Android.mk
index 0e1fbfd..38c8056 100644
--- a/twmincrypt/Android.mk
+++ b/twmincrypt/Android.mk
@@ -8,4 +8,9 @@
 LOCAL_MODULE_TAGS:= eng
 LOCAL_MODULE := libmincrypt
 LOCAL_SRC_FILES := ../../../system/core/libmincrypt/rsa.c ../../../system/core/libmincrypt/sha.c
+
+ifneq ($(wildcard system/core/libmincrypt/rsa_e_3.c),)
+LOCAL_SRC_FILES += ../../../system/core/libmincrypt/rsa_e_3.c ../../../system/core/libmincrypt/rsa_e_f4.c
+endif
+
 include $(BUILD_SHARED_LIBRARY)