diff --git a/library.properties b/library.properties
index f2c3def6..b7a8ddfa 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=RadioLib
-version=3.7.0
+version=4.0.0
 author=Jan Gromes <gromes.jan@gmail.com>
 maintainer=Jan Gromes <gromes.jan@gmail.com>
 sentence=Universal wireless communication library for Arduino
diff --git a/src/BuildOpt.h b/src/BuildOpt.h
index dfbaf26d..66697fac 100644
--- a/src/BuildOpt.h
+++ b/src/BuildOpt.h
@@ -333,8 +333,8 @@
 
 
 // version definitions
-#define RADIOLIB_VERSION_MAJOR  (0x03)
-#define RADIOLIB_VERSION_MINOR  (0x07)
+#define RADIOLIB_VERSION_MAJOR  (0x04)
+#define RADIOLIB_VERSION_MINOR  (0x00)
 #define RADIOLIB_VERSION_PATCH  (0x00)
 #define RADIOLIB_VERSION_EXTRA  (0x00)