diff --git a/src/libstore/filetransfer.cc b/src/libstore/filetransfer.cc
index 6b9c6602b..304984d99 100644
--- a/src/libstore/filetransfer.cc
+++ b/src/libstore/filetransfer.cc
@@ -394,9 +394,11 @@ struct curlFileTransfer : public FileTransfer
                 if (request.method == HttpMethod::POST) {
                     curl_easy_setopt(req, CURLOPT_POST, 1L);
                     curl_easy_setopt(req, CURLOPT_POSTFIELDSIZE_LARGE, (curl_off_t) request.data->length());
-                } else {
+                } else if (request.method == HttpMethod::PUT) {
                     curl_easy_setopt(req, CURLOPT_UPLOAD, 1L);
                     curl_easy_setopt(req, CURLOPT_INFILESIZE_LARGE, (curl_off_t) request.data->length());
+                } else {
+                    unreachable();
                 }
                 curl_easy_setopt(req, CURLOPT_READFUNCTION, readCallbackWrapper);
                 curl_easy_setopt(req, CURLOPT_READDATA, this);
diff --git a/src/libstore/http-binary-cache-store.cc b/src/libstore/http-binary-cache-store.cc
index 1f9ee4100..4b8276572 100644
--- a/src/libstore/http-binary-cache-store.cc
+++ b/src/libstore/http-binary-cache-store.cc
@@ -141,7 +141,7 @@ void HttpBinaryCacheStore::upsertFile(
     uint64_t sizeHint)
 {
     auto req = makeRequest(path);
-
+    req.method = HttpMethod::PUT;
     auto data = StreamToSourceAdapter(istream).drain();
 
     auto compressionMethod = getCompressionMethod(path);
diff --git a/src/libstore/include/nix/store/filetransfer.hh b/src/libstore/include/nix/store/filetransfer.hh
index 305c33af1..08a2b6329 100644
--- a/src/libstore/include/nix/store/filetransfer.hh
+++ b/src/libstore/include/nix/store/filetransfer.hh
@@ -88,6 +88,7 @@ extern const unsigned int RETRY_TIME_MS_DEFAULT;
  */
 enum struct HttpMethod {
     GET,
+    PUT,
     HEAD,
     POST,
     DELETE,
@@ -147,7 +148,9 @@ struct FileTransferRequest
         case HttpMethod::HEAD:
         case HttpMethod::GET:
             return "download";
+        case HttpMethod::PUT:
         case HttpMethod::POST:
+            assert(data);
             return "upload";
         case HttpMethod::DELETE:
             return "delet";
diff --git a/src/libstore/s3-binary-cache-store.cc b/src/libstore/s3-binary-cache-store.cc
index 828e75b7c..417355b68 100644
--- a/src/libstore/s3-binary-cache-store.cc
+++ b/src/libstore/s3-binary-cache-store.cc
@@ -101,6 +101,7 @@ std::string
 S3BinaryCacheStore::uploadPart(std::string_view key, std::string_view uploadId, uint64_t partNumber, std::string data)
 {
     auto req = makeRequest(key);
+    req.method = HttpMethod::PUT;
     req.setupForS3();
 
     auto url = req.uri.parsed();