diff --git a/src/libstore/download.cc b/src/libstore/download.cc
index f93fb1e96..d65ac7b87 100644
--- a/src/libstore/download.cc
+++ b/src/libstore/download.cc
@@ -201,7 +201,7 @@ struct CurlDownloader : public Downloader
             curl_easy_setopt(req, CURLOPT_URL, request.uri.c_str());
             curl_easy_setopt(req, CURLOPT_FOLLOWLOCATION, 1L);
             curl_easy_setopt(req, CURLOPT_NOSIGNAL, 1);
-            curl_easy_setopt(req, CURLOPT_USERAGENT, ("Nix/" + nixVersion).c_str());
+            curl_easy_setopt(req, CURLOPT_USERAGENT, ("curl/" LIBCURL_VERSION " Nix/" + nixVersion).c_str());
             #if LIBCURL_VERSION_NUM >= 0x072b00
             curl_easy_setopt(req, CURLOPT_PIPEWAIT, 1);
             #endif