diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index c107254..ce2916d 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -52,6 +52,8 @@
 
 # These are the current development codenames, if the build is not a final
 # release build.  If this is a final release build, it is simply "REL".
+# Note that this may be overridden by RELEASE_VERSION_CODENAME_REL in
+# version_util.mk.
 PLATFORM_VERSION_CODENAME.UP1A := UpsideDownCake
 PLATFORM_VERSION_CODENAME.VP1A := VanillaIceCream
 
diff --git a/core/version_util.mk b/core/version_util.mk
index d3fcdc2..457f0f7 100644
--- a/core/version_util.mk
+++ b/core/version_util.mk
@@ -56,6 +56,12 @@
 # unreleased API level targetable by this branch, not just those that are valid
 # lunch targets for this branch.
 
+# Release config flag to override the current version to REL.  Note that the
+# codename can also be locked to REL by setting it in versino_defaults.mk.
+ifneq ($(RELEASE_PLATFORM_VERSION_CODENAME_REL),)
+  PLATFORM_VERSION_CODENAME.$(TARGET_PLATFORM_VERSION) := REL
+endif
+
 PLATFORM_VERSION_CODENAME := $(PLATFORM_VERSION_CODENAME.$(TARGET_PLATFORM_VERSION))
 ifndef PLATFORM_VERSION_CODENAME
   # PLATFORM_VERSION_CODENAME falls back to TARGET_PLATFORM_VERSION