diff --git a/src/libstore-tests/data/serve-protocol/handshake-to-client.bin b/src/libstore-tests/data/serve-protocol/handshake-to-client.bin
index 15ba4b5e3..465daa532 100644
Binary files a/src/libstore-tests/data/serve-protocol/handshake-to-client.bin and b/src/libstore-tests/data/serve-protocol/handshake-to-client.bin differ
diff --git a/src/libstore-tests/serve-protocol.cc b/src/libstore-tests/serve-protocol.cc
index 01d6058cb..4cd7f101b 100644
--- a/src/libstore-tests/serve-protocol.cc
+++ b/src/libstore-tests/serve-protocol.cc
@@ -20,9 +20,9 @@ struct ServeProtoTest : VersionedProtoTest<ServeProto, serveProtoDir>
 {
     /**
      * For serializers that don't care about the minimum version, we
-     * used the oldest one: 1.0.
+     * used the oldest one: 2.5.
      */
-    ServeProto::Version defaultVersion = 2 << 8 | 0;
+    ServeProto::Version defaultVersion = 2 << 8 | 5;
 };
 
 VERSIONED_CHARACTERIZATION_TEST(
diff --git a/src/libstore/include/nix/store/serve-protocol-connection.hh b/src/libstore/include/nix/store/serve-protocol-connection.hh
index fa50132c8..873277db9 100644
--- a/src/libstore/include/nix/store/serve-protocol-connection.hh
+++ b/src/libstore/include/nix/store/serve-protocol-connection.hh
@@ -82,8 +82,6 @@ struct ServeProto::BasicClientConnection
     BuildResult getBuildDerivationResponse(const StoreDirConfig & store);
 
     void narFromPath(const StoreDirConfig & store, const StorePath & path, std::function<void(Source &)> fun);
-
-    void importPaths(const StoreDirConfig & store, std::function<void(Sink &)> fun);
 };
 
 struct ServeProto::BasicServerConnection
diff --git a/src/libstore/include/nix/store/serve-protocol.hh b/src/libstore/include/nix/store/serve-protocol.hh
index c8f3560d1..4c2043f17 100644
--- a/src/libstore/include/nix/store/serve-protocol.hh
+++ b/src/libstore/include/nix/store/serve-protocol.hh
@@ -108,8 +108,6 @@ enum struct ServeProto::Command : uint64_t {
     QueryValidPaths = 1,
     QueryPathInfos = 2,
     DumpStorePath = 3,
-    ImportPaths = 4,
-    ExportPaths = 5,
     BuildPaths = 6,
     QueryClosure = 7,
     BuildDerivation = 8,
diff --git a/src/libstore/legacy-ssh-store.cc b/src/libstore/legacy-ssh-store.cc
index d42dca74a..f935de206 100644
--- a/src/libstore/legacy-ssh-store.cc
+++ b/src/libstore/legacy-ssh-store.cc
@@ -105,9 +105,6 @@ std::map<StorePath, UnkeyedValidPathInfo> LegacySSHStore::queryPathInfosUncached
 {
     auto conn(connections->get());
 
-    /* No longer support missing NAR hash */
-    assert(GET_PROTOCOL_MINOR(conn->remoteVersion) >= 4);
-
     debug(
         "querying remote host '%s' for info on '%s'",
         config->authority.host,
@@ -152,40 +149,21 @@ void LegacySSHStore::addToStore(const ValidPathInfo & info, Source & source, Rep
 
     auto conn(connections->get());
 
-    if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 5) {
-
-        conn->to << ServeProto::Command::AddToStoreNar << printStorePath(info.path)
-                 << (info.deriver ? printStorePath(*info.deriver) : "")
-                 << info.narHash.to_string(HashFormat::Base16, false);
-        ServeProto::write(*this, *conn, info.references);
-        conn->to << info.registrationTime << info.narSize << info.ultimate << info.sigs
-                 << renderContentAddress(info.ca);
-        try {
-            copyNAR(source, conn->to);
-        } catch (...) {
-            conn->good = false;
-            throw;
-        }
-        conn->to.flush();
-
-        if (readInt(conn->from) != 1)
-            throw Error(
-                "failed to add path '%s' to remote host '%s'", printStorePath(info.path), config->authority.host);
-
-    } else {
-
-        conn->importPaths(*this, [&](Sink & sink) {
-            try {
-                copyNAR(source, sink);
-            } catch (...) {
-                conn->good = false;
-                throw;
-            }
-            sink << exportMagic << printStorePath(info.path);
-            ServeProto::write(*this, *conn, info.references);
-            sink << (info.deriver ? printStorePath(*info.deriver) : "") << 0 << 0;
-        });
+    conn->to << ServeProto::Command::AddToStoreNar << printStorePath(info.path)
+             << (info.deriver ? printStorePath(*info.deriver) : "")
+             << info.narHash.to_string(HashFormat::Base16, false);
+    ServeProto::write(*this, *conn, info.references);
+    conn->to << info.registrationTime << info.narSize << info.ultimate << info.sigs << renderContentAddress(info.ca);
+    try {
+        copyNAR(source, conn->to);
+    } catch (...) {
+        conn->good = false;
+        throw;
     }
+    conn->to.flush();
+
+    if (readInt(conn->from) != 1)
+        throw Error("failed to add path '%s' to remote host '%s'", printStorePath(info.path), config->authority.host);
 }
 
 void LegacySSHStore::narFromPath(const StorePath & path, Sink & sink)
diff --git a/src/libstore/serve-protocol-connection.cc b/src/libstore/serve-protocol-connection.cc
index 908994f4e..a90b104a6 100644
--- a/src/libstore/serve-protocol-connection.cc
+++ b/src/libstore/serve-protocol-connection.cc
@@ -15,7 +15,7 @@ ServeProto::Version ServeProto::BasicClientConnection::handshake(
     if (magic != SERVE_MAGIC_2)
         throw Error("'nix-store --serve' protocol mismatch from '%s'", host);
     auto remoteVersion = readInt(from);
-    if (GET_PROTOCOL_MAJOR(remoteVersion) != 0x200)
+    if (GET_PROTOCOL_MAJOR(remoteVersion) != 0x200 || GET_PROTOCOL_MINOR(remoteVersion) < 5)
         throw Error("unsupported 'nix-store --serve' protocol version on '%s'", host);
     return std::min(remoteVersion, localVersion);
 }
@@ -93,14 +93,4 @@ void ServeProto::BasicClientConnection::narFromPath(
     fun(from);
 }
 
-void ServeProto::BasicClientConnection::importPaths(const StoreDirConfig & store, std::function<void(Sink &)> fun)
-{
-    to << ServeProto::Command::ImportPaths;
-    fun(to);
-    to.flush();
-
-    if (readInt(from) != 1)
-        throw Error("remote machine failed to import closure");
-}
-
 } // namespace nix
diff --git a/src/nix/nix-store/nix-store.cc b/src/nix/nix-store/nix-store.cc
index 4191ea0d6..3ab9b7583 100644
--- a/src/nix/nix-store/nix-store.cc
+++ b/src/nix/nix-store/nix-store.cc
@@ -985,20 +985,6 @@ static void opServe(Strings opFlags, Strings opArgs)
             store->narFromPath(store->parseStorePath(readString(in)), out);
             break;
 
-        case ServeProto::Command::ImportPaths: {
-            if (!writeAllowed)
-                throw Error("importing paths is not allowed");
-            store->importPaths(in, NoCheckSigs); // FIXME: should we skip sig checking?
-            out << 1;                            // indicate success
-            break;
-        }
-
-        case ServeProto::Command::ExportPaths: {
-            readInt(in); // obsolete
-            store->exportPaths(ServeProto::Serialise<StorePathSet>::read(*store, rconn), out);
-            break;
-        }
-
         case ServeProto::Command::BuildPaths: {
 
             if (!writeAllowed)