diff --git a/flake.lock b/flake.lock
index ee85f6fa..4b18fbb4 100644
--- a/flake.lock
+++ b/flake.lock
@@ -42,16 +42,16 @@
         "nixpkgs-regression": "nixpkgs-regression"
       },
       "locked": {
-        "lastModified": 1686048923,
-        "narHash": "sha256-/XCWa2osNFIpPC5MkxlX6qTZf/DaTLwS3LWN0SRFiuU=",
+        "lastModified": 1690219894,
+        "narHash": "sha256-QMYAkdtU+g9HlZKtoJ+AI6TbWzzovKGnPZJHfZdclc8=",
         "owner": "NixOS",
         "repo": "nix",
-        "rev": "84050709ea18f3285a85d729f40c8f8eddf5008e",
+        "rev": "a212300a1d9f9c7b0daf19c00c87fc50480f54f4",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "2.16.1",
+        "ref": "2.17.0",
         "repo": "nix",
         "type": "github"
       }
diff --git a/flake.nix b/flake.nix
index 6bbec9b0..7e7d50e2 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,7 +2,7 @@
   description = "A Nix-based continuous build system";
 
   inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.05";
-  inputs.nix.url = "github:NixOS/nix/2.16.1";
+  inputs.nix.url = "github:NixOS/nix/2.17.0";
   inputs.nix.inputs.nixpkgs.follows = "nixpkgs";
 
   outputs = { self, nixpkgs, nix }:
diff --git a/src/hydra-queue-runner/build-remote.cc b/src/hydra-queue-runner/build-remote.cc
index 6baff7df..6bbd22e2 100644
--- a/src/hydra-queue-runner/build-remote.cc
+++ b/src/hydra-queue-runner/build-remote.cc
@@ -6,6 +6,7 @@
 #include <fcntl.h>
 
 #include "build-result.hh"
+#include "path.hh"
 #include "serve-protocol.hh"
 #include "state.hh"
 #include "util.hh"
@@ -110,18 +111,20 @@ static void copyClosureTo(std::timed_mutex & sendMutex, Store & destStore,
     StorePathSet closure;
     destStore.computeFSClosure(paths, closure);
 
+    WorkerProto::WriteConn wconn { .to = to };
+    WorkerProto::ReadConn rconn { .from = from };
     /* Send the "query valid paths" command with the "lock" option
        enabled. This prevents a race where the remote host
        garbage-collect paths that are already there. Optionally, ask
        the remote host to substitute missing paths. */
     // FIXME: substitute output pollutes our build log
-    to << cmdQueryValidPaths << 1 << useSubstitutes;
-    workerProtoWrite(destStore, to, closure);
+    to << ServeProto::Command::QueryValidPaths << 1 << useSubstitutes;
+    WorkerProto::write(destStore, wconn, closure);
     to.flush();
 
     /* Get back the set of paths that are already valid on the remote
        host. */
-    auto present = WorkerProto<StorePathSet>::read(destStore, from);
+    auto present = WorkerProto::Serialise<StorePathSet>::read(destStore, rconn);
 
     if (present.size() == closure.size()) return;
 
@@ -136,7 +139,7 @@ static void copyClosureTo(std::timed_mutex & sendMutex, Store & destStore,
     std::unique_lock<std::timed_mutex> sendLock(sendMutex,
         std::chrono::seconds(600));
 
-    to << cmdImportPaths;
+    to << ServeProto::Command::ImportPaths;
     destStore.exportPaths(missing, to);
     to.flush();
 
@@ -223,7 +226,9 @@ void State::buildRemote(ref<Store> destStore,
         });
 
         FdSource from(child.from.get());
+        WorkerProto::ReadConn rconn { .from = from };
         FdSink to(child.to.get());
+        WorkerProto::WriteConn wconn { .to = to };
 
         Finally updateStats([&]() {
             bytesReceived += from.read;
@@ -334,7 +339,7 @@ void State::buildRemote(ref<Store> destStore,
 
         updateStep(ssBuilding);
 
-        to << cmdBuildDerivation << localStore->printStorePath(step->drvPath);
+        to << ServeProto::Command::BuildDerivation << localStore->printStorePath(step->drvPath);
         writeDerivation(to, *localStore, basicDrv);
         to << maxSilentTime << buildTimeout;
         if (GET_PROTOCOL_MINOR(remoteVersion) >= 2)
@@ -367,7 +372,7 @@ void State::buildRemote(ref<Store> destStore,
             }
         }
         if (GET_PROTOCOL_MINOR(remoteVersion) >= 6) {
-            WorkerProto<DrvOutputs>::read(*localStore, from);
+          WorkerProto::Serialise<DrvOutputs>::read(*localStore, rconn);
         }
         switch ((BuildResult::Status) res) {
             case BuildResult::Built:
@@ -443,14 +448,14 @@ void State::buildRemote(ref<Store> destStore,
             /* Get info about each output path. */
             std::map<StorePath, ValidPathInfo> infos;
             size_t totalNarSize = 0;
-            to << cmdQueryPathInfos;
-            workerProtoWrite(*localStore, to, outputs);
+            to << ServeProto::Command::QueryPathInfos;
+            WorkerProto::write(*localStore, wconn, outputs);
             to.flush();
             while (true) {
                 auto storePathS = readString(from);
                 if (storePathS == "") break;
                 auto deriver = readString(from); // deriver
-                auto references = WorkerProto<StorePathSet>::read(*localStore, from);
+                auto references = WorkerProto::Serialise<StorePathSet>::read(*localStore, rconn);
                 readLongLong(from); // download size
                 auto narSize = readLongLong(from);
                 auto narHash = Hash::parseAny(readString(from), htSHA256);
@@ -494,7 +499,7 @@ void State::buildRemote(ref<Store> destStore,
                        lambda function only gets executed if someone tries to read
                        from source2, we will send the command from here rather
                        than outside the lambda. */
-                    to << cmdDumpStorePath << localStore->printStorePath(path);
+                    to << ServeProto::Command::DumpStorePath << localStore->printStorePath(path);
                     to.flush();
 
                     TeeSource tee(from, sink);