diff --git a/src/gb/Makefile.am b/src/gb/Makefile.am
index 70caa1f..dd0d213 100644
--- a/src/gb/Makefile.am
+++ b/src/gb/Makefile.am
@@ -1,6 +1,6 @@
 # This is _NOT_ the library release version, it's an API version.
 # Please read Chapter 6 "Library interface versions" of the libtool documentation before making any modification
-LIBVERSION=3:1:0
+LIBVERSION=4:0:0
 
 AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_builddir)/include
 AM_CFLAGS = -Wall ${GCC_FVISIBILITY_HIDDEN} -fno-strict-aliasing