diff --git a/bloaty/bloaty.go b/bloaty/bloaty.go
index 21bf4acf1..653c4890a 100644
--- a/bloaty/bloaty.go
+++ b/bloaty/bloaty.go
@@ -22,7 +22,7 @@ import (
 	"github.com/google/blueprint"
 )
 
-const bloatyDescriptorExt = "bloaty.csv"
+const bloatyDescriptorExt = ".bloaty.csv"
 const protoFilename = "binary_sizes.pb"
 
 var (
@@ -75,7 +75,7 @@ func (singleton *sizesSingleton) GenerateBuildActions(ctx android.SingletonConte
 			return
 		}
 		filePath := ctx.ModuleProvider(m, fileSizeMeasurerKey).(android.ModuleOutPath)
-		sizeFile := filePath.ReplaceExtension(ctx, bloatyDescriptorExt)
+		sizeFile := filePath.InSameDir(ctx, filePath.Base()+bloatyDescriptorExt)
 		ctx.Build(pctx, android.BuildParams{
 			Rule:        bloaty,
 			Description: "bloaty " + filePath.Rel(),