diff --git a/core/android_soong_config_vars.mk b/core/android_soong_config_vars.mk
index 39f0155..9d7c1bf 100644
--- a/core/android_soong_config_vars.mk
+++ b/core/android_soong_config_vars.mk
@@ -82,7 +82,7 @@
   # This sets the default for building ART APEXes from source rather than
   # prebuilts (in packages/modules/ArtPrebuilt and prebuilt/module_sdk/art) in
   # all other platform builds.
-  SOONG_CONFIG_art_module_source_build ?= false
+  SOONG_CONFIG_art_module_source_build ?= true
 endif
 
 # Apex build mode variables
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 663579a..31c30b6 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -93,7 +93,7 @@
 
 # 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".
-PLATFORM_VERSION_CODENAME.SP1A := REL
+PLATFORM_VERSION_CODENAME.SP1A := S
 
 ifndef PLATFORM_VERSION_CODENAME
   PLATFORM_VERSION_CODENAME := $(PLATFORM_VERSION_CODENAME.$(TARGET_PLATFORM_VERSION))