diff --git a/PID_v1.h b/PID_v1.h
index 77b3e4b..bc52f96 100644
--- a/PID_v1.h
+++ b/PID_v1.h
@@ -1,6 +1,6 @@
 #ifndef PID_v1_h
 #define PID_v1_h
-#define LIBRARY_VERSION	1.1.1
+#define PID_LIBRARY_VERSION	1.1.1
 
 class PID
 {