diff --git a/tests/Makefile b/tests/Makefile
index 1512fa7..50a0549 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -6,7 +6,8 @@
 WARNING_CFLAGS ?= -Wall -W -Wdeclaration-after-statement -Wno-unused-function -Wno-unused-value
 LDFLAGS ?=
 
-LOCAL_CFLAGS = $(WARNING_CFLAGS) -I../include -I../library -D_FILE_OFFSET_BITS=64
+CRYPTO_INCLUDES ?= -I../include
+LOCAL_CFLAGS = $(WARNING_CFLAGS) $(CRYPTO_INCLUDES) -I../library -D_FILE_OFFSET_BITS=64
 LOCAL_LDFLAGS = -L../library			\
 		-lmbedtls$(SHARED_SUFFIX)	\
 		-lmbedx509$(SHARED_SUFFIX)	\