diff --git a/README.md b/README.md
index e87f0c0..cfe2907 100644
--- a/README.md
+++ b/README.md
@@ -36,8 +36,8 @@
     git clone https://github.com/WiringPi/WiringPi.git
     cd WiringPi
     ./build
-    cd ~/Danger-alarm/SERVER/hc-12
-    make clean; make
+    cd ~/Danger-alarm/SERVER/libconf && make clean; make
+    cd ~/Danger-alarm/SERVER/hc-12 && make clean; make
     ./hc-12
     
 ```
diff --git a/SERVER/hc-12/Makefile b/SERVER/hc-12/Makefile
index 315fe5f..c683f4e 100644
--- a/SERVER/hc-12/Makefile
+++ b/SERVER/hc-12/Makefile
@@ -17,5 +17,5 @@ hc-12:  hc-12.o ../libconf/libconf.o mysql.o
 	$(CC) $(CFLAGS) $(MYSQL_CFLAGS) -c $< $@
     
 clean:
-	rm hc-12 hc-12.o ../libconf/libconf.o mysql.o
+	rm hc-12 *.o