diff --git a/VERSION b/VERSION
index d5c0c991..fcdb2e10 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-3.5.1
+4.0.0
diff --git a/docs/user_guide.md b/docs/user_guide.md
index a005e51c..0233a30f 100644
--- a/docs/user_guide.md
+++ b/docs/user_guide.md
@@ -207,6 +207,7 @@ http://www.nws.noaa.gov/tdl/iwt/grib2/frameset_grib2.htm.
 
 ## Documentation for Previous Versions of NCEPLIBS-g2
 
+* [NCEPLIBS-g2 Version 3.5.1](ver-3.5.1/index.html)
 * [NCEPLIBS-g2 Version 3.5.0](ver-3.5.0/index.html)
 * [NCEPLIBS-g2 Version 3.4.9](ver-3.4.9/index.html)
 * [NCEPLIBS-g2 Version 3.4.8](ver-3.4.8/index.html)