diff --git a/java/androidmk.go b/java/androidmk.go
index bc327cf..f0e6357 100644
--- a/java/androidmk.go
+++ b/java/androidmk.go
@@ -127,9 +127,8 @@
 						entries.AddStrings("LOCAL_ADDITIONAL_CHECKED_MODULE", library.additionalCheckedModules.Strings()...)
 					}
 
-					if library.dexer.proguardDictionary.Valid() {
-						entries.SetPath("LOCAL_SOONG_PROGUARD_DICT", library.dexer.proguardDictionary.Path())
-					}
+					entries.SetOptionalPath("LOCAL_SOONG_PROGUARD_DICT", library.dexer.proguardDictionary)
+					entries.SetOptionalPath("LOCAL_SOONG_PROGUARD_USAGE_ZIP", library.dexer.proguardUsageZip)
 					entries.SetString("LOCAL_MODULE_STEM", library.Stem())
 
 					entries.SetOptionalPaths("LOCAL_SOONG_LINT_REPORTS", library.linter.reports)
@@ -332,9 +331,8 @@
 				if app.jacocoReportClassesFile != nil {
 					entries.SetPath("LOCAL_SOONG_JACOCO_REPORT_CLASSES_JAR", app.jacocoReportClassesFile)
 				}
-				if app.dexer.proguardDictionary.Valid() {
-					entries.SetPath("LOCAL_SOONG_PROGUARD_DICT", app.dexer.proguardDictionary.Path())
-				}
+				entries.SetOptionalPath("LOCAL_SOONG_PROGUARD_DICT", app.dexer.proguardDictionary)
+				entries.SetOptionalPath("LOCAL_SOONG_PROGUARD_USAGE_ZIP", app.dexer.proguardUsageZip)
 
 				if app.Name() == "framework-res" {
 					entries.SetString("LOCAL_MODULE_PATH", "$(TARGET_OUT_JAVA_LIBRARIES)")
diff --git a/java/dex.go b/java/dex.go
index cd45a93..c85914c 100644
--- a/java/dex.go
+++ b/java/dex.go
@@ -72,6 +72,7 @@
 	// list of extra proguard flag files
 	extraProguardFlagFiles android.Paths
 	proguardDictionary     android.OptionalPath
+	proguardUsageZip       android.OptionalPath
 }
 
 func (d *dexer) effectiveOptimizeEnabled() bool {
@@ -109,13 +110,17 @@
 var r8, r8RE = remoteexec.MultiCommandStaticRules(pctx, "r8",
 	blueprint.RuleParams{
 		Command: `rm -rf "$outDir" && mkdir -p "$outDir" && ` +
-			`rm -f "$outDict" && ` +
+			`rm -f "$outDict" && rm -rf "${outUsageDir}" && ` +
+			`mkdir -p $$(dirname ${outUsage}) && ` +
 			`$r8Template${config.R8Cmd} ${config.DexFlags} -injars $in --output $outDir ` +
 			`--force-proguard-compatibility ` +
 			`--no-data-resources ` +
-			`-printmapping $outDict ` +
+			`-printmapping ${outDict} ` +
+			`-printusage ${outUsage} ` +
 			`$r8Flags && ` +
-			`touch "$outDict" && ` +
+			`touch "${outDict}" "${outUsage}" && ` +
+			`${config.SoongZipCmd} -o ${outUsageZip} -C ${outUsageDir} -f ${outUsage} && ` +
+			`rm -rf ${outUsageDir} && ` +
 			`$zipTemplate${config.SoongZipCmd} $zipFlags -o $outDir/classes.dex.jar -C $outDir -f "$outDir/classes*.dex" && ` +
 			`${config.MergeZipsCmd} -D -stripFile "**/*.class" $out $outDir/classes.dex.jar $in`,
 		CommandDeps: []string{
@@ -138,7 +143,15 @@
 			ExecStrategy: "${config.RER8ExecStrategy}",
 			Platform:     map[string]string{remoteexec.PoolKey: "${config.REJavaPool}"},
 		},
-	}, []string{"outDir", "outDict", "r8Flags", "zipFlags"}, []string{"implicits"})
+		"$zipUsageTemplate": &remoteexec.REParams{
+			Labels:       map[string]string{"type": "tool", "name": "soong_zip"},
+			Inputs:       []string{"${config.SoongZipCmd}", "${outUsage}"},
+			OutputFiles:  []string{"${outUsageZip}"},
+			ExecStrategy: "${config.RER8ExecStrategy}",
+			Platform:     map[string]string{remoteexec.PoolKey: "${config.REJavaPool}"},
+		},
+	}, []string{"outDir", "outDict", "outUsage", "outUsageZip", "outUsageDir",
+		"r8Flags", "zipFlags"}, []string{"implicits"})
 
 func (d *dexer) dexCommonFlags(ctx android.ModuleContext, minSdkVersion sdkSpec) []string {
 	flags := d.dexProperties.Dxflags
@@ -259,26 +272,34 @@
 	if useR8 {
 		proguardDictionary := android.PathForModuleOut(ctx, "proguard_dictionary")
 		d.proguardDictionary = android.OptionalPathForPath(proguardDictionary)
+		proguardUsageDir := android.PathForModuleOut(ctx, "proguard_usage")
+		proguardUsage := proguardUsageDir.Join(ctx, ctx.Namespace().Path,
+			android.ModuleNameWithPossibleOverride(ctx), "unused.txt")
+		proguardUsageZip := android.PathForModuleOut(ctx, "proguard_usage.zip")
+		d.proguardUsageZip = android.OptionalPathForPath(proguardUsageZip)
 		r8Flags, r8Deps := d.r8Flags(ctx, flags)
 		rule := r8
 		args := map[string]string{
-			"r8Flags":  strings.Join(append(commonFlags, r8Flags...), " "),
-			"zipFlags": zipFlags,
-			"outDict":  proguardDictionary.String(),
-			"outDir":   outDir.String(),
+			"r8Flags":     strings.Join(append(commonFlags, r8Flags...), " "),
+			"zipFlags":    zipFlags,
+			"outDict":     proguardDictionary.String(),
+			"outUsageDir": proguardUsageDir.String(),
+			"outUsage":    proguardUsage.String(),
+			"outUsageZip": proguardUsageZip.String(),
+			"outDir":      outDir.String(),
 		}
 		if ctx.Config().IsEnvTrue("RBE_R8") {
 			rule = r8RE
 			args["implicits"] = strings.Join(r8Deps.Strings(), ",")
 		}
 		ctx.Build(pctx, android.BuildParams{
-			Rule:           rule,
-			Description:    "r8",
-			Output:         javalibJar,
-			ImplicitOutput: proguardDictionary,
-			Input:          classesJar,
-			Implicits:      r8Deps,
-			Args:           args,
+			Rule:            rule,
+			Description:     "r8",
+			Output:          javalibJar,
+			ImplicitOutputs: android.WritablePaths{proguardDictionary, proguardUsageZip},
+			Input:           classesJar,
+			Implicits:       r8Deps,
+			Args:            args,
 		})
 	} else {
 		d8Flags, d8Deps := d8Flags(flags)