diff --git a/configure.ac b/configure.ac
index 67472b2..c707765 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,7 +1,7 @@
 # Process this file with autoconf to produce a configure script.
 
 AC_PREREQ([2.59])
-AC_INIT(titan2d, 3.99.7)
+AC_INIT(titan2d, 4.0.0)
 AM_INIT_AUTOMAKE
 
 ## Check is portable package is made
diff --git a/src/header/titan2d.h b/src/header/titan2d.h
index fb6ffe6..032f8b0 100644
--- a/src/header/titan2d.h
+++ b/src/header/titan2d.h
@@ -18,9 +18,9 @@
 #ifndef TITAN2D
 #define TITAN2D
 
-#define TITAN2D_VERSION_MAJOR 3
-#define TITAN2D_VERSION_MINOR 99
-#define TITAN2D_VERSION_REVISION 7
+#define TITAN2D_VERSION_MAJOR 4
+#define TITAN2D_VERSION_MINOR 0
+#define TITAN2D_VERSION_REVISION 0
 
 extern int threads_number;