diff --git a/integration-tests/test_extensions.py b/integration-tests/test_extensions.py
index e351a09..e071279 100644
--- a/integration-tests/test_extensions.py
+++ b/integration-tests/test_extensions.py
@@ -13,7 +13,7 @@ def test_serverextensions():
     ], stderr=subprocess.PIPE)
 
     extensions = [
-        'jupyterlab 0.35.4',
+        'jupyterlab 1.2.6',
         'nbgitpuller 0.6.1',
         'nteract_on_jupyter 2.0.7',
         'nbresuse '
@@ -51,3 +51,4 @@ def test_labextensions():
     """
     # Currently we only install jupyterhub
     assert os.path.exists('/opt/tljh/user/bin/jupyter-labhub')
+    
\ No newline at end of file
diff --git a/tljh/installer.py b/tljh/installer.py
index 0e8b2ac..e533a82 100644
--- a/tljh/installer.py
+++ b/tljh/installer.py
@@ -170,14 +170,13 @@ def ensure_jupyterlab_extensions():
     Install the JupyterLab extensions we want.
     """
     extensions = [
-        '@jupyterlab/hub-extension',
-        '@jupyter-widgets/jupyterlab-manager'
+        '@jupyter-widgets/jupyterlab-manager@1.1' # for jupyterlab 1.2.x
     ]
     utils.run_subprocess([
         os.path.join(USER_ENV_PREFIX, 'bin/jupyter'),
         'labextension',
         'install'
-    ] + extensions)
+    ] + extensions + ['--minimize=False']) # webpack minimization might cause flaky test build
 
 
 def ensure_jupyterhub_package(prefix):
@@ -263,7 +262,7 @@ def ensure_user_environment(user_requirements_txt_file):
         'jupyterhub==1.0.0',
         'notebook==5.7.8',
         # Install additional notebook frontends!
-        'jupyterlab==0.35.4',
+        'jupyterlab==1.2.6',
         'nteract-on-jupyter==2.0.7',
         # nbgitpuller for easily pulling in Git repositories
         'nbgitpuller==0.6.1',