diff --git a/apex/bp2build.go b/apex/bp2build.go
index d28f512..a3dda83 100644
--- a/apex/bp2build.go
+++ b/apex/bp2build.go
@@ -15,16 +15,22 @@
 
 import (
 	"android/soong/android"
+	"encoding/json"
 	"strings"
 )
 
 // This file contains the bp2build integration for the apex package.
 
 // Export constants as Starlark using bp2build to Bazel.
-func BazelApexToolchainVars() string {
+func BazelApexToolchainVars() (string, error) {
+	marshalled, err := json.Marshal(apexAvailBaseline)
+	if err != nil {
+		return "", err
+	}
 	content := []string{
 		"# GENERATED BY SOONG. DO NOT EDIT.",
 		"default_manifest_version = " + android.DefaultUpdatableModuleVersion, // constants.go is different in every branch.
+		"apex_available_baseline = json.decode('''" + string(marshalled) + "''')",
 	}
-	return strings.Join(content, "\n")
+	return strings.Join(content, "\n"), nil
 }