diff --git a/charms/jimm/charmcraft.yaml b/charms/jimm/charmcraft.yaml
index 03e50dd2f..884b923b5 100644
--- a/charms/jimm/charmcraft.yaml
+++ b/charms/jimm/charmcraft.yaml
@@ -9,7 +9,7 @@ parts:
       - README.md
     charm-python-packages: [setuptools]
     charm-binary-python-packages:
-      - pydantic
+      - pydantic == 1.10.10
       - cosl
 bases:
   # Ensure run-on is the same or newer than build-on
diff --git a/charms/jimm/lib/charms/grafana_agent/v0/cos_agent.py b/charms/jimm/lib/charms/grafana_agent/v0/cos_agent.py
index 0acaed361..b2d0d2719 100644
--- a/charms/jimm/lib/charms/grafana_agent/v0/cos_agent.py
+++ b/charms/jimm/lib/charms/grafana_agent/v0/cos_agent.py
@@ -191,7 +191,7 @@ class _MetricsEndpointDict(TypedDict):
 LIBAPI = 0
 LIBPATCH = 3
 
-PYDEPS = ["cosl", "pydantic"]
+PYDEPS = ["cosl", "pydantic == 1.10.10"]
 
 DEFAULT_RELATION_NAME = "cos-agent"
 DEFAULT_PEER_RELATION_NAME = "peers"