diff --git a/mediaapi/routing/download.go b/mediaapi/routing/download.go
index 648e3f1e9..d74229356 100644
--- a/mediaapi/routing/download.go
+++ b/mediaapi/routing/download.go
@@ -15,12 +15,12 @@
 package routing
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"fmt"
 	"io"
 	"io/ioutil"
-	"bytes"
 	"mime"
 	"net/http"
 	"net/url"
@@ -675,6 +675,36 @@ func (r *downloadRequest) fetchRemoteFileAndStoreMetadata(
 	return nil
 }
 
+func (r *downloadRequest) GetContentLengthAndReader(contentLengthHeader string, body *io.ReadCloser) (int64, io.Reader, error) {
+	var reader io.Reader
+	var contentLength int64
+
+	if contentLengthHeader != "" {
+		parsedLength, parseErr := strconv.ParseInt(contentLengthHeader, 10, 64)
+
+		if parseErr != nil {
+			r.Logger.WithError(parseErr).Warn("Failed to parse content length")
+			return 0, nil, errors.Wrap(parseErr, "invalid response from remote server")
+		}
+
+		reader = *body
+		contentLength = parsedLength
+	} else {
+		// Content-Length header is missing, we need to read the whole body to get its length
+		bodyBytes, readAllErr := ioutil.ReadAll(*body)
+		if readAllErr != nil {
+			r.Logger.WithError(readAllErr).Warn("Could not read response body from remote server")
+			return 0, nil, errors.Wrap(readAllErr, "invalid response from remote server")
+		}
+
+		contentLength = int64(len(bodyBytes))
+		reader = ioutil.NopCloser(bytes.NewBuffer(bodyBytes))
+	}
+
+	return contentLength, reader, nil
+
+}
+
 func (r *downloadRequest) fetchRemoteFile(
 	ctx context.Context,
 	client *gomatrixserverlib.Client,
@@ -694,31 +724,11 @@ func (r *downloadRequest) fetchRemoteFile(
 	}
 	defer resp.Body.Close() // nolint: errcheck
 
-	var reader io.Reader
-	var contentLength int64
-	
-	if resp.Header.Get("Content-Length") != "" {
-		parsedLength, err := strconv.ParseInt(resp.Header.Get("Content-Length"), 10, 64)
-
-		if err != nil {
-			r.Logger.WithError(err).Warn("Failed to parse content length")
-			return "", false, errors.Wrap(err, "invalid response from remote server")
-		}
-
-		reader = resp.Body
-		contentLength = parsedLength
-	} else {
-		// Content-Length header is missing, we need to read the whole body to get its length
-		bodyBytes, err := ioutil.ReadAll(resp.Body)
-		if err != nil {
-			r.Logger.WithError(err).Warn("Could not read response body from remote server")	
-			return "", false, fmt.Errorf("file could not be downloaded from remote server")
-		}
-
-		contentLength = int64(len(bodyBytes))
-		reader = ioutil.NopCloser(bytes.NewBuffer(bodyBytes))		
+	contentLength, reader, parseErr := r.GetContentLengthAndReader(resp.Header.Get("Content-Length"), &resp.Body)
+	if parseErr != nil {
+		return "", false, parseErr
 	}
-	
+
 	if contentLength > int64(maxFileSizeBytes) {
 		// TODO: Bubble up this as a 413
 		return "", false, fmt.Errorf("remote file is too large (%v > %v bytes)", contentLength, maxFileSizeBytes)