diff --git a/src/libstore/download.cc b/src/libstore/download.cc
index 8030e83b0dd5cf2acb867a0db41074252e32640d..074e0ca6642aea7c061e4c5419ac3bf14ff8e2fe 100644
--- a/src/libstore/download.cc
+++ b/src/libstore/download.cc
@@ -276,7 +276,7 @@ struct CurlDownloader : public Downloader
                     code == CURLE_ABORTED_BY_CALLBACK && _isInterrupted
                     ? DownloadError(Interrupted, format("download of ‘%s’ was interrupted") % request.uri)
                     : httpStatus != 0
-                      ? DownloadError(err, format("unable to download ‘%s’: HTTP error %d") % request.uri % httpStatus)
+                      ? DownloadError(err, format("unable to download ‘%s’: HTTP error %d (curl error: %s)") % request.uri % httpStatus % curl_easy_strerror(code))
                       : DownloadError(err, format("unable to download ‘%s’: %s (%d)") % request.uri % curl_easy_strerror(code) % code);
 
                 /* If this is a transient error, then maybe retry the