diff --git a/java/dexpreopt.go b/java/dexpreopt.go
index e588c9a..998730e 100644
--- a/java/dexpreopt.go
+++ b/java/dexpreopt.go
@@ -16,6 +16,7 @@
 
 import (
 	"path/filepath"
+	"sort"
 	"strings"
 
 	"android/soong/android"
@@ -390,11 +391,37 @@
 
 	globalSoong := dexpreopt.GetGlobalSoongConfig(ctx)
 
-	// "product_packages.txt" is generated by `build/make/core/Makefile`.
+	// The root "product_packages.txt" is generated by `build/make/core/Makefile`. It contains a list
+	// of all packages that are installed on the device. We use `grep` to filter the list by the app's
+	// dependencies to create a per-app list, and use `rsync --checksum` to prevent the file's mtime
+	// from being changed if the contents don't change. This avoids unnecessary dexpreopt reruns.
 	productPackages := android.PathForModuleInPartitionInstall(ctx, "", "product_packages.txt")
+	appProductPackages := android.PathForModuleOut(ctx, "dexpreopt", "product_packages.txt")
+	appProductPackagesStaging := appProductPackages.ReplaceExtension(ctx, "txt.tmp")
+	clcNames, _ := dexpreopt.ComputeClassLoaderContextDependencies(dexpreoptConfig.ClassLoaderContexts)
+	sort.Strings(clcNames) // The order needs to be deterministic.
+	productPackagesRule := android.NewRuleBuilder(pctx, ctx)
+	if len(clcNames) > 0 {
+		productPackagesRule.Command().
+			Text("grep -F -x").
+			FlagForEachArg("-e ", clcNames).
+			Input(productPackages).
+			FlagWithOutput("> ", appProductPackagesStaging).
+			Text("|| true")
+	} else {
+		productPackagesRule.Command().
+			Text("rm -f").Output(appProductPackagesStaging).
+			Text("&&").
+			Text("touch").Output(appProductPackagesStaging)
+	}
+	productPackagesRule.Command().
+		Text("rsync --checksum").
+		Input(appProductPackagesStaging).
+		Output(appProductPackages)
+	productPackagesRule.Restat().Build("product_packages", "dexpreopt product_packages")
 
 	dexpreoptRule, err := dexpreopt.GenerateDexpreoptRule(
-		ctx, globalSoong, global, dexpreoptConfig, productPackages)
+		ctx, globalSoong, global, dexpreoptConfig, appProductPackages)
 	if err != nil {
 		ctx.ModuleErrorf("error generating dexpreopt rule: %s", err.Error())
 		return