diff --git a/lib/charms/data_platform_libs/v0/upgrade.py b/lib/charms/data_platform_libs/v0/upgrade.py
index b8c753776b..670f4652e5 100644
--- a/lib/charms/data_platform_libs/v0/upgrade.py
+++ b/lib/charms/data_platform_libs/v0/upgrade.py
@@ -285,7 +285,7 @@ def restart(self, event) -> None:
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
-LIBPATCH = 13
+LIBPATCH = 14
 
 PYDEPS = ["pydantic>=1.10,<2", "poetry-core"]
 
@@ -895,6 +895,10 @@ def _on_upgrade_charm(self, event: UpgradeCharmEvent) -> None:
             self.charm.unit.status = WaitingStatus("other units upgrading first...")
             self.peer_relation.data[self.charm.unit].update({"state": "ready"})
 
+            if self.charm.app.planned_units() == 1:
+                # single unit upgrade, emit upgrade_granted event right away
+                getattr(self.on, "upgrade_granted").emit()
+
         else:
             # for k8s run version checks only on highest ordinal unit
             if (
diff --git a/lib/charms/postgresql_k8s/v0/postgresql.py b/lib/charms/postgresql_k8s/v0/postgresql.py
index 7df406de0f..bfda780e8c 100644
--- a/lib/charms/postgresql_k8s/v0/postgresql.py
+++ b/lib/charms/postgresql_k8s/v0/postgresql.py
@@ -19,7 +19,7 @@
 Any charm using this library should import the `psycopg2` or `psycopg2-binary` dependency.
 """
 import logging
-from typing import List, Optional, Set, Tuple
+from typing import Dict, List, Optional, Set, Tuple
 
 import psycopg2
 from psycopg2 import sql
@@ -32,7 +32,7 @@
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
-LIBPATCH = 15
+LIBPATCH = 16
 
 INVALID_EXTRA_USER_ROLE_BLOCKING_MESSAGE = "invalid role(s) for extra user roles"
 
@@ -441,7 +441,7 @@ def is_restart_pending(self) -> bool:
     @staticmethod
     def build_postgresql_parameters(
         profile: str, available_memory: int, limit_memory: Optional[int] = None
-    ) -> Optional[dict[str, str]]:
+    ) -> Optional[Dict[str, str]]:
         """Builds the PostgreSQL parameters.
 
         Args: