diff --git a/build/soong/build_files.go b/build/soong/build_files.go
index 1704366..88c07fa 100644
--- a/build/soong/build_files.go
+++ b/build/soong/build_files.go
@@ -188,4 +188,12 @@
 		// reqd_mask is needed for public policies
 		b.srcs["."+p.String()+"_public"] = b.findSrcsInDirs(ctx, append(gatherDirsFor(p, public), reqdMaskDir)...)
 	}
+
+	// A special tag, "plat_vendor", includes minimized vendor policies required to boot.
+	//   - system/sepolicy/public
+	//   - system/sepolicy/reqd_mask
+	//   - system/sepolicy/vendor
+	// This is for minimized vendor partition, e.g. microdroid's vendor
+	platVendorDir := filepath.Join(ctx.ModuleDir(), "vendor")
+	b.srcs[".plat_vendor"] = b.findSrcsInDirs(ctx, append(gatherDirsFor(system, public), reqdMaskDir, platVendorDir)...)
 }