diff --git a/src/libstore/filetransfer.cc b/src/libstore/filetransfer.cc
index d20fb2b17..02ac9e067 100644
--- a/src/libstore/filetransfer.cc
+++ b/src/libstore/filetransfer.cc
@@ -835,7 +835,7 @@ void FileTransfer::download(
            buffer). We don't wait forever to prevent stalling the
            download thread. (Hopefully sleeping will throttle the
            sender.) */
-        if (state->data.size() > 1024 * 1024) {
+        if (state->data.size() > fileTransferSettings.downloadBufferSize) {
             debug("download buffer is full; going to sleep");
             state.wait_for(state->request, std::chrono::seconds(10));
         }
diff --git a/src/libstore/filetransfer.hh b/src/libstore/filetransfer.hh
index 1c271cbec..221a2b0ea 100644
--- a/src/libstore/filetransfer.hh
+++ b/src/libstore/filetransfer.hh
@@ -45,6 +45,12 @@ struct FileTransferSettings : Config
 
     Setting<unsigned int> tries{this, 5, "download-attempts",
         "How often Nix will attempt to download a file before giving up."};
+
+    Setting<size_t> downloadBufferSize{this, 64 * 1024 * 1024, "download-buffer-size",
+        R"(
+          The size of Nix's internal download buffer during `curl` transfers. If data is
+          not processed quickly enough to exceed the size of this buffer, downloads may stall.
+        )"};
 };
 
 extern FileTransferSettings fileTransferSettings;