diff --git a/plugins/endpoints/migrations/versions/0019_split_shipped_monitor_policies.py b/plugins/endpoints/migrations/versions/0019_split_shipped_monitor_policies.py
index 69d1028b..92ea28dd 100644
--- a/plugins/endpoints/migrations/versions/0019_split_shipped_monitor_policies.py
+++ b/plugins/endpoints/migrations/versions/0019_split_shipped_monitor_policies.py
@@ -39,7 +39,7 @@ Idempotent on the policy names, so a re-run neither duplicates the split rows
 nor resurrects the bundle. Guards on the policy tables being present and no-ops
 if they are not, matching 0007.
 
-Revision ID: endpoints0019splitmonitorpolicies
+Revision ID: endpoints0019splitpolicies
 Revises: endpoints0018endpointlocks
 """
 from alembic import op
@@ -49,7 +49,9 @@ import sqlalchemy as sa
 from datetime import datetime
 
 
-revision = 'endpoints0019splitmonitorpolicies'
+# Alembic stores this in alembic_version.version_num, a VARCHAR(32). A longer
+# id passes on SQLite and fails on strict MySQL with "Data too long".
+revision = 'endpoints0019splitpolicies'
 down_revision = 'endpoints0018endpointlocks'
 branch_labels = None
 depends_on = None
diff --git a/tests/test_plugin_migrations.py b/tests/test_plugin_migrations.py
index 146c748a..36930f35 100644
--- a/tests/test_plugin_migrations.py
+++ b/tests/test_plugin_migrations.py
@@ -115,7 +115,7 @@ EXPECTED_HEAD_REVISION['warranty'] = 'warranty0002proof'
 # on one endpoint, a caller-authority axis separate from the policy hold.
 # 0019 splits the 0007 bundle into one shipped Configuration Policy per monitor
 # and drops the shipped Business Policy, so sites compose their own.
-EXPECTED_HEAD_REVISION['endpoints'] = 'endpoints0019splitmonitorpolicies'
+EXPECTED_HEAD_REVISION['endpoints'] = 'endpoints0019splitpolicies'
 
 # Plugins built after the cutover: their 0001 baseline really creates tables the
 # core chain never owned.
@@ -208,6 +208,17 @@ def test_plugin_has_migration_chain(plugin):
                     if isinstance(node.value, ast.Constant):
                         down = node.value.value
         assert rev, f"{plugin}: {script.name} has no revision id"
+        # alembic_version_<plugin>.version_num is VARCHAR(32). A longer id
+        # passes every SQLite test and then fails the real deploy on strict
+        # MySQL with "Data too long for column 'version_num'", after the
+        # migration body has already run. Caught
+        # endpoints0019splitmonitorpolicies (33 chars) during a container roll.
+        # The CORE chain's alembic_version is VARCHAR(128), so core ids are not
+        # bound by this and are not checked here.
+        assert len(rev) <= 32, (
+            f"{plugin}: {script.name} revision id {rev!r} is {len(rev)} chars; "
+            'alembic_version.version_num holds 32'
+        )
         assert found_down, f"{plugin}: {script.name} has no down_revision"
         revisions.add(rev)
         if down is None: