diff --git a/cylc/uiserver/__init__.py b/cylc/uiserver/__init__.py
index 7019f5a2..7414bc32 100644
--- a/cylc/uiserver/__init__.py
+++ b/cylc/uiserver/__init__.py
@@ -13,7 +13,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-__version__ = "1.4.1.dev"
+__version__ = "1.5.0.dev"
 
 import os
 from typing import Dict
diff --git a/setup.cfg b/setup.cfg
index a0229f15..6195c3c3 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -49,7 +49,7 @@ install_requires =
     # bleeding-edge version.
     # NB: no graphene version specified; we only make light use of it in our
     # own code, so graphene-tornado's transitive version should do.
-    cylc-flow==8.2.*
+    cylc-flow==8.3.*
     ansimarkup>=1.0.0
     graphene
     graphene-tornado==2.6.*