diff --git a/report/azureblob.go b/report/azureblob.go
index 5636298b..a466db8c 100644
--- a/report/azureblob.go
+++ b/report/azureblob.go
@@ -136,7 +136,7 @@ func createBlockBlob(cli storage.BlobStorageClient, k string, b []byte) error {
 		if b, err = gz(b); err != nil {
 			return err
 		}
-		k = k + ".gz"
+		k += ".gz"
 	}
 
 	ref := cli.GetContainerReference(c.Conf.Azure.ContainerName)
diff --git a/report/localfile.go b/report/localfile.go
index d121e885..d658b935 100644
--- a/report/localfile.go
+++ b/report/localfile.go
@@ -129,7 +129,7 @@ func writeFile(path string, data []byte, perm os.FileMode) error {
 		if data, err = gz(data); err != nil {
 			return err
 		}
-		path = path + ".gz"
+		path += ".gz"
 	}
 	return ioutil.WriteFile(path, []byte(data), perm)
 }
diff --git a/report/s3.go b/report/s3.go
index 66ba587c..e72abaac 100644
--- a/report/s3.go
+++ b/report/s3.go
@@ -144,7 +144,7 @@ func putObject(svc *s3.S3, k string, b []byte) error {
 		if b, err = gz(b); err != nil {
 			return err
 		}
-		k = k + ".gz"
+		k += ".gz"
 	}
 
 	putObjectInput := &s3.PutObjectInput{