diff --git a/3rdparty/p256-m/Makefile.inc b/3rdparty/p256-m/Makefile.inc
index fc8f73b..53bb55b 100644
--- a/3rdparty/p256-m/Makefile.inc
+++ b/3rdparty/p256-m/Makefile.inc
@@ -1,5 +1,5 @@
-THIRDPARTY_INCLUDES+=-I../3rdparty/p256-m/p256-m/include -I../3rdparty/p256-m/p256-m/include/p256-m -I../3rdparty/p256-m/p256-m_driver_interface
+THIRDPARTY_INCLUDES+=-I$(THIRDPARTY_DIR)/p256-m/p256-m/include -I$(THIRDPARTY_DIR)/p256-m/p256-m/include/p256-m -I$(THIRDPARTY_DIR)/p256-m/p256-m_driver_interface
 
 THIRDPARTY_CRYPTO_OBJECTS+= \
-	../3rdparty/p256-m//p256-m_driver_entrypoints.o \
-	../3rdparty/p256-m//p256-m/p256-m.o
+	$(THIRDPARTY_DIR)/p256-m//p256-m_driver_entrypoints.o \
+	$(THIRDPARTY_DIR)/p256-m//p256-m/p256-m.o