diff --git a/packages/agoric-cli/integration-tests/test-workflow.js b/packages/agoric-cli/integration-tests/test-workflow.js
index 677d20e5d06..f14e4f5cc6e 100644
--- a/packages/agoric-cli/integration-tests/test-workflow.js
+++ b/packages/agoric-cli/integration-tests/test-workflow.js
@@ -137,7 +137,7 @@ test('workflow', async t => {
       ]);
       finalizers.push(() => pkill(deployP.cp, 'SIGINT'));
 
-      timeout = setTimeout(deployResult.resolve, 30000, 'timeout');
+      timeout = setTimeout(deployResult.resolve, 60000, 'timeout');
       const done = await Promise.race([deployResult.promise, deployP]);
       t.equals(done, 0, `deploy successful before timeout`);
       clearTimeout(timeout);
diff --git a/packages/agoric-cli/lib/install.js b/packages/agoric-cli/lib/install.js
index 5add1f35151..8f5f7727285 100644
--- a/packages/agoric-cli/lib/install.js
+++ b/packages/agoric-cli/lib/install.js
@@ -5,6 +5,9 @@ export default async function installMain(progname, rawArgs, powers, opts) {
   const { anylogger, fs, spawn } = powers;
   const log = anylogger('agoric:install');
 
+  // Notify the preinstall guard that we are running.
+  process.env.AGORIC_INSTALL = 'true';
+
   const pspawn = (...args) =>
     new Promise((resolve, _reject) => {
       const cp = spawn(...args);
@@ -15,36 +18,105 @@ export default async function installMain(progname, rawArgs, powers, opts) {
   const rimraf = file => pspawn('rm', ['-rf', file]);
   const subdirs = ['.', '_agstate/agoric-servers', 'contract', 'api'].sort();
 
+  const linkFolder = path.resolve(`_agstate/yarn-links`);
+  const linkFlags = [`--link-folder=${linkFolder}`, 'link'];
+
   if (opts.sdk) {
-    const sdkNodeModules = path.resolve(__dirname, '../../../node_modules');
+    const sdkPackagesDir = path.resolve(__dirname, '../../../packages');
+    const allPackages = await fs.readdir(sdkPackagesDir);
+    const packages = new Map();
+    const versions = new Map();
+    log('removing', linkFolder);
+    await rimraf(linkFolder);
+    for (const pkg of allPackages) {
+      const dir = `${sdkPackagesDir}/${pkg}`;
+      let packageJSON;
+      try {
+        // eslint-disable-next-line no-await-in-loop
+        packageJSON = await fs.readFile(`${dir}/package.json`);
+      } catch (e) {
+        // eslint-disable-next-line no-continue
+        continue;
+      }
+      if (packageJSON) {
+        const pj = JSON.parse(packageJSON);
+        if (!pj.private) {
+          if (
+            // eslint-disable-next-line no-await-in-loop
+            await pspawn('yarn', linkFlags, {
+              stdio: 'inherit',
+              cwd: dir,
+            })
+          ) {
+            log.error('Cannot yarn link', dir);
+            return 1;
+          }
+          packages.set(pkg, pj.name);
+          versions.set(pj.name, pj.version);
+        }
+      }
+    }
     await Promise.all(
-      subdirs.map(subdir => {
+      subdirs.map(async subdir => {
         const nm = `${subdir}/node_modules`;
-        log(chalk.bold.green(`removing ${nm}`));
-        return rimraf(nm).then(_ => {
-          log(chalk.bold.green(`link SDK ${nm}`));
-          return fs.symlink(sdkNodeModules, nm);
-        });
+        log(chalk.bold.green(`removing ${nm} link`));
+        await fs.unlink(nm).catch(_ => {});
+
+        // Update all the package dependencies according to the SDK.
+        const pjson = `${subdir}/package.json`;
+        const packageJSON = await fs.readFile(pjson);
+        const pj = JSON.parse(packageJSON);
+        for (const section of ['dependencies', 'devDependencies']) {
+          const deps = pj[section];
+          if (deps) {
+            for (const pkg of Object.keys(deps)) {
+              const latest = versions.get(pkg);
+              if (latest) {
+                deps[pkg] = `^${latest}`;
+              }
+            }
+          }
+        }
+        log.info(`updating ${pjson}`);
+        await fs.writeFile(pjson, `${JSON.stringify(pj, null, 2)}\n`);
       }),
     );
+    const sdkPackages = [...packages.values()].sort();
+    for (const subdir of subdirs) {
+      if (
+        // eslint-disable-next-line no-await-in-loop
+        await pspawn('yarn', [...linkFlags, ...sdkPackages], {
+          stdio: 'inherit',
+          cwd: subdir,
+        })
+      ) {
+        log.error('Cannot yarn link', ...sdkPackages);
+        return 1;
+      }
+    }
   } else {
-    // Delete any symlinks.
+    // Delete all old node_modules.
     await Promise.all(
       subdirs.map(subdir => {
         const nm = `${subdir}/node_modules`;
         log(chalk.bold.green(`removing ${nm}`));
-        return fs.unlink(nm).catch(_ => {});
+        return rimraf(nm);
       }),
     );
+  }
 
-    if (await pspawn('yarn', ['install'], { stdio: 'inherit' })) {
-      // Try to install via Yarn.
-      log.error('Cannot yarn install');
-      return 1;
-    }
+  if (await pspawn('yarn', [linkFlags[0], 'install'], { stdio: 'inherit' })) {
+    // Try to install via Yarn.
+    log.error('Cannot yarn install');
+    return 1;
   }
 
-  if (await pspawn('yarn', ['install'], { stdio: 'inherit', cwd: 'ui' })) {
+  if (
+    await pspawn('yarn', [linkFlags[0], 'install'], {
+      stdio: 'inherit',
+      cwd: 'ui',
+    })
+  ) {
     // Try to install via Yarn.
     log.warn('Cannot yarn install in ui directory');
     return 1;