diff --git a/lib/docker.js b/lib/docker.js
index 4951f8db867b1b12b75af79be2ebae6165534960..b333e65e99a9ef420826c0b1a908d4923dffc2f6 100644
--- a/lib/docker.js
+++ b/lib/docker.js
@@ -12,7 +12,6 @@ var EventEmitter = require('events').EventEmitter,
   Node = require('./node'),
   Exec = require('./exec'),
   util = require('./util'),
-  withSession = require('./session'),
   extend = util.extend;
 
 var Docker = function(opts) {
@@ -301,6 +300,12 @@ Docker.prototype.buildImage = function(file, opts, callback) {
 
   function dialWithSession(callback) {
     if (opts?.version === "2") {
+      // Loaded here rather than at module scope: './session' pulls in @grpc/grpc-js and
+      // @grpc/proto-loader (112 files), which cost +6.0 MiB RSS on top of dockerode itself.
+      // Only the BuildKit image-build path reaches this branch, so listing or starting
+      // containers paid for a gRPC stack it never used. require() is cached, so builds behave
+      // exactly as before.
+      var withSession = require('./session');
       withSession(self, optsf.authconfig,(err, sessionId, done) => {
         if (err) {
           return callback(err);