diff --git a/Makefile b/Makefile
index f67ae0f..bbb79cc 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,7 @@ OBJS += gen/bitmaps.o
 OBJS += gen/fonts.o
 
 libtrezor.a: $(OBJS)
-	ar rcs libtrezor.a $(OBJS)
+	$(AR) rcs libtrezor.a $(OBJS)
 
 include Makefile.include
 
diff --git a/Makefile.include b/Makefile.include
index f931984..0f46d7d 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -6,6 +6,7 @@ CC      = $(PREFIX)gcc
 LD      = $(PREFIX)gcc
 OBJCOPY = $(PREFIX)objcopy
 OBJDUMP = $(PREFIX)objdump
+AR      = $(PREFIX)ar
 FLASH   = st-flash
 OPENOCD = openocd