diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index 3addc1a..2a84f14 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -262,7 +262,7 @@
 	apex, isApexModule := module.(android.ApexModule)
 	fromUpdatableApex := isApexModule && apex.Updatable()
 	if image.name == artBootImageName {
-		if isApexModule && len(apex.InApexes()) > 0 && allHavePrefix(apex.InApexes(), "com.android.art.") {
+		if isApexModule && strings.HasPrefix(apex.ApexVariationName(), "com.android.art.") {
 			// ok: found the jar in the ART apex
 		} else if isApexModule && apex.IsForPlatform() && Bool(module.(*Library).deviceProperties.Hostdex) {
 			// exception (skip and continue): special "hostdex" platform variant
@@ -272,17 +272,17 @@
 			return -1, nil
 		} else if fromUpdatableApex {
 			// error: this jar is part of an updatable apex other than ART
-			ctx.Errorf("module %q from updatable apexes %q is not allowed in the ART boot image", name, apex.InApexes())
+			ctx.Errorf("module '%s' from updatable apex '%s' is not allowed in the ART boot image", name, apex.ApexVariationName())
 		} else {
 			// error: this jar is part of the platform or a non-updatable apex
-			ctx.Errorf("module %q is not allowed in the ART boot image", name)
+			ctx.Errorf("module '%s' is not allowed in the ART boot image", name)
 		}
 	} else if image.name == frameworkBootImageName {
 		if !fromUpdatableApex {
 			// ok: this jar is part of the platform or a non-updatable apex
 		} else {
 			// error: this jar is part of an updatable apex
-			ctx.Errorf("module %q from updatable apexes %q is not allowed in the framework boot image", name, apex.InApexes())
+			ctx.Errorf("module '%s' from updatable apex '%s' is not allowed in the framework boot image", name, apex.ApexVariationName())
 		}
 	} else {
 		panic("unknown boot image: " + image.name)
@@ -291,15 +291,6 @@
 	return index, jar.DexJarBuildPath()
 }
 
-func allHavePrefix(list []string, prefix string) bool {
-	for _, s := range list {
-		if !strings.HasPrefix(s, prefix) {
-			return false
-		}
-	}
-	return true
-}
-
 // buildBootImage takes a bootImageConfig, creates rules to build it, and returns the image.
 func buildBootImage(ctx android.SingletonContext, image *bootImageConfig) *bootImageConfig {
 	// Collect dex jar paths for the boot image modules.