diff --git a/Makefile b/Makefile
index 50bcacd..9abd9ff 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,8 @@
 
 SOURCES = $(wildcard *.c) \
 	drivers/serial/pcserialport.c \
-	drivers/tcpip/tcpclient.c
+	drivers/tcpip/tcpclient.c \
+	utils/crc.c
 
 OBJECTS = $(SOURCES:%.c=%.o)
 
diff --git a/tests/Makefile b/tests/Makefile
index 0e248be..ec7b462 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -48,4 +48,4 @@ $(LIB_OUTDIR)/%.o: ../%.c
 
 clean:
 	rm -f $(OBJ) $(LIB_OBJECTS) $(TEST_CASES) libsimplemotionv2.a
-	rmdir $(LIB_OUTDIR)
+	rm -rf $(LIB_OUTDIR)