diff --git a/RELEASE b/RELEASE
index 9b601acc0d..5186d07068 100644
--- a/RELEASE
+++ b/RELEASE
@@ -1 +1 @@
-3.4.git
+4.0
diff --git a/doc/Doxyfile b/doc/Doxyfile
index 0891899505..ccec314d3e 100644
--- a/doc/Doxyfile
+++ b/doc/Doxyfile
@@ -38,7 +38,7 @@ PROJECT_NAME           = FFmpeg
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         =
+PROJECT_NUMBER         = 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