diff --git a/java/builder.go b/java/builder.go
index f1d5e99..22dad10 100644
--- a/java/builder.go
+++ b/java/builder.go
@@ -750,9 +750,9 @@
 	jar android.Path) {
 
 	ctx.Build(pctx, android.BuildParams{
-		Rule:        extractR8Rules,
-		Output:      outputFile,
-		Input:       jar,
+		Rule:   extractR8Rules,
+		Output: outputFile,
+		Input:  jar,
 	})
 }
 
@@ -796,7 +796,7 @@
 	totalStr := strconv.Itoa(totalShards)
 	for i := 0; i < totalShards; i++ {
 		iStr := strconv.Itoa(i)
-		tempOut := android.PathForOutput(ctx, outputFile.String()+"-"+iStr+".jar")
+		tempOut := outputFile.ReplaceExtension(ctx, "-"+iStr+".jar")
 		ctx.Build(pctx, android.BuildParams{
 			Rule:        jarjar,
 			Description: "jarjar (" + iStr + "/" + totalStr + ")",