diff --git a/appveyor.yml b/appveyor.yml
index 2b80300b9..0d48abdb5 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -2,7 +2,7 @@
 #if you want to work on this, please talk with us on
 # https://lists.sourceforge.net/lists/listinfo/audacity-devel
 #build time is circa 7 mins.
-version: 2.3.3-alpha-{build}
+version: 2.4.0-alpha-{build}
 image: Visual Studio 2017
 shallow_clone: true # reduce traffic
 install:
diff --git a/audacity.dox b/audacity.dox
index 7318670fe..b246d688f 100644
--- a/audacity.dox
+++ b/audacity.dox
@@ -38,7 +38,7 @@ PROJECT_NAME           = Audacity
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 2.3.3
+PROJECT_NUMBER         = 2.4.0
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a
diff --git a/configure.ac b/configure.ac
index 40fc32668..22a3f81dd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -34,7 +34,7 @@ dnl Require autoconf >= 2.59
 AC_PREREQ([2.59])
 
 dnl Init autoconf
-AC_INIT([audacity], [2.3.3])
+AC_INIT([audacity], [2.4.0])
 dnl Check for existence of Audacity.h
 AC_CONFIG_SRCDIR([src/Audacity.h])
 AC_CONFIG_AUX_DIR([autotools])
diff --git a/src/Audacity.h b/src/Audacity.h
index 4a680ed33..6589aa63e 100644
--- a/src/Audacity.h
+++ b/src/Audacity.h
@@ -39,7 +39,7 @@
 // Its value may be more than 0 for pre-release "Beta" builds that differ only
 // in the welcome screen, and hiding of some development menu commands, but
 // still link to the alpha manual online.
-#define AUDACITY_BUILD_LEVEL 2
+#define AUDACITY_BUILD_LEVEL 0
 
 // used #ifdef not #if for IS_ALPHA, IS_BETA, IS_RELEASE, USE_ALPHA_MANUAL
 #undef IS_ALPHA
@@ -61,8 +61,8 @@
 
 // Increment as appropriate every time we release a NEW version.
 #define AUDACITY_VERSION   2
-#define AUDACITY_RELEASE   3
-#define AUDACITY_REVISION  3
+#define AUDACITY_RELEASE   4
+#define AUDACITY_REVISION  0
 #define AUDACITY_MODLEVEL  0
 
 #if defined(IS_BETA)