diff --git a/tools/usb/Makefile b/tools/usb/Makefile
index 396d6c4..acf2165 100644
--- a/tools/usb/Makefile
+++ b/tools/usb/Makefile
@@ -3,11 +3,12 @@
 CC = $(CROSS_COMPILE)gcc
 PTHREAD_LIBS = -lpthread
 WARNINGS = -Wall -Wextra
-CFLAGS = $(WARNINGS) -g $(PTHREAD_LIBS) -I../include
+CFLAGS = $(WARNINGS) -g -I../include
+LDFLAGS = $(PTHREAD_LIBS)
 
 all: testusb ffs-test
 %: %.c
-	$(CC) $(CFLAGS) -o $@ $^
+	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
 
 clean:
 	$(RM) testusb ffs-test