diff --git a/src/libstore/builtins/fetchurl.cc b/src/libstore/builtins/fetchurl.cc
index e263997e1..06ab0505a 100644
--- a/src/libstore/builtins/fetchurl.cc
+++ b/src/libstore/builtins/fetchurl.cc
@@ -36,7 +36,7 @@ void builtinFetchurl(const BasicDerivation & drv, const std::string & netrcData,
 
     auto fetch = [&](const std::string & url) {
 
-        auto raw = fileTransfer->download(url);
+        auto raw = fileTransfer->download(url).second;
         auto decompressor = makeDecompressionSource(
             unpack && mainUrl.ends_with(".xz") ? "xz" : "none", *raw);
 
diff --git a/src/libstore/filetransfer.cc b/src/libstore/filetransfer.cc
index 73bae6cfe..1f6c3e22b 100644
--- a/src/libstore/filetransfer.cc
+++ b/src/libstore/filetransfer.cc
@@ -821,7 +821,8 @@ struct curlFileTransfer : public FileTransfer
         }
     }
 
-    box_ptr<Source> download(const std::string & uri, const Headers & headers) override
+    std::pair<FileTransferResult, box_ptr<Source>>
+    download(const std::string & uri, const Headers & headers) override
     {
         struct State {
             bool done = false, failed = false;
@@ -832,7 +833,7 @@ struct curlFileTransfer : public FileTransfer
 
         auto _state = std::make_shared<Sync<State>>();
 
-        auto transfer = enqueueFileTransfer(
+        auto [metadataFuture, _done] = enqueueFileTransfer(
             uri,
             headers,
             [_state](std::exception_ptr ex) {
@@ -939,10 +940,11 @@ struct curlFileTransfer : public FileTransfer
             }
         };
 
+        auto metadata = metadataFuture.get();
         auto source = make_box_ptr<DownloadSource>(_state);
         auto lock(_state->lock());
         source->awaitData(lock);
-        return source;
+        return {std::move(metadata), std::move(source)};
     }
 };
 
diff --git a/src/libstore/filetransfer.hh b/src/libstore/filetransfer.hh
index 8ee88a7a8..1abc07c4d 100644
--- a/src/libstore/filetransfer.hh
+++ b/src/libstore/filetransfer.hh
@@ -101,7 +101,8 @@ struct FileTransfer
      * thrown by the returned source. The source will only throw errors detected
      * during the transfer itself (decompression errors, connection drops, etc).
      */
-    virtual box_ptr<Source> download(const std::string & uri, const Headers & headers = {}) = 0;
+    virtual std::pair<FileTransferResult, box_ptr<Source>>
+    download(const std::string & uri, const Headers & headers = {}) = 0;
 
     enum Error { NotFound, Forbidden, Misc, Transient, Interrupted };
 };
diff --git a/src/libstore/http-binary-cache-store.cc b/src/libstore/http-binary-cache-store.cc
index 80524b58d..9e81cd156 100644
--- a/src/libstore/http-binary-cache-store.cc
+++ b/src/libstore/http-binary-cache-store.cc
@@ -147,7 +147,7 @@ protected:
     {
         checkEnabled();
         try {
-            return getFileTransfer()->download(makeURI(path));
+            return getFileTransfer()->download(makeURI(path)).second;
         } catch (FileTransferError & e) {
             if (e.error == FileTransfer::NotFound || e.error == FileTransfer::Forbidden)
                 throw NoSuchBinaryCacheFile("file '%s' does not exist in binary cache '%s'", path, getUri());
diff --git a/src/nix/prefetch.cc b/src/nix/prefetch.cc
index 1fb7bb49b..686df2caa 100644
--- a/src/nix/prefetch.cc
+++ b/src/nix/prefetch.cc
@@ -98,7 +98,7 @@ std::tuple<StorePath, Hash> prefetchFile(
 
             FdSink sink(fd.get());
 
-            getFileTransfer()->download(url)->drainInto(sink);
+            getFileTransfer()->download(url).second->drainInto(sink);
         }
 
         /* Optionally unpack the file. */
diff --git a/tests/unit/libstore/filetransfer.cc b/tests/unit/libstore/filetransfer.cc
index 0e0a2439e..dd0c33f06 100644
--- a/tests/unit/libstore/filetransfer.cc
+++ b/tests/unit/libstore/filetransfer.cc
@@ -136,7 +136,7 @@ TEST(FileTransfer, exceptionAbortsDownload)
 
     LambdaSink broken([](auto block) { throw Done(); });
 
-    ASSERT_THROW(ft->download("file:///dev/zero")->drainInto(broken), Done);
+    ASSERT_THROW(ft->download("file:///dev/zero").second->drainInto(broken), Done);
 
     // makeFileTransfer returns a ref<>, which cannot be cleared. since we also
     // can't default-construct it we'll have to overwrite it instead, but we'll
@@ -155,7 +155,7 @@ TEST(FileTransfer, exceptionAbortsRead)
     auto [port, srv] = serveHTTP("200 ok", "content-length: 0\r\n", [] { return ""; });
     auto ft = makeFileTransfer();
     char buf[10] = "";
-    ASSERT_THROW(ft->download(fmt("http://[::1]:%d/index", port))->read(buf, 10), EndOfFile);
+    ASSERT_THROW(ft->download(fmt("http://[::1]:%d/index", port)).second->read(buf, 10), EndOfFile);
 }
 
 TEST(FileTransfer, NOT_ON_DARWIN(reportsSetupErrors))
@@ -179,7 +179,7 @@ TEST(FileTransfer, NOT_ON_DARWIN(defersFailures))
         return std::string(1024 * 1024, ' ');
     });
     auto ft = makeFileTransfer(0);
-    auto src = ft->download(fmt("http://[::1]:%d/index", port));
+    auto src = ft->download(fmt("http://[::1]:%d/index", port)).second;
     ASSERT_THROW(src->drain(), FileTransferError);
 }
 
@@ -192,7 +192,7 @@ TEST(FileTransfer, NOT_ON_DARWIN(handlesContentEncoding))
     auto ft = makeFileTransfer();
 
     StringSink sink;
-    ft->download(fmt("http://[::1]:%d/index", port))->drainInto(sink);
+    ft->download(fmt("http://[::1]:%d/index", port)).second->drainInto(sink);
     EXPECT_EQ(sink.s, original);
 }