diff --git a/lower-constraints.txt b/lower-constraints.txt
index ea9f8bc0f..6d91f0b5b 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -40,7 +40,7 @@ os-traits==2.7.0
 oslo.concurrency==3.26.0
 oslo.config==6.7.0
 oslo.context==2.22.0
-oslo.db==4.40.0
+oslo.db==8.6.0
 oslo.i18n==3.20.0
 oslo.log==4.3.0
 oslo.middleware==3.31.0
@@ -74,7 +74,7 @@ requestsexceptions==1.4.0
 rfc3986==0.3.1
 Routes==2.3.1
 smmap2==2.0.3
-SQLAlchemy==1.2.19
+SQLAlchemy==1.4.0
 setuptools==21.0.0
 sqlparse==0.2.4
 statsd==3.2.2
diff --git a/placement/objects/allocation.py b/placement/objects/allocation.py
index 4c32954d8..fbdce051e 100644
--- a/placement/objects/allocation.py
+++ b/placement/objects/allocation.py
@@ -127,7 +127,7 @@ def _check_capacity_exceeded(ctx, allocs):
                 _ALLOC_TBL.c.resource_provider_id.in_(provider_ids)))
     usage = usage.group_by(_ALLOC_TBL.c.resource_provider_id,
                            _ALLOC_TBL.c.resource_class_id)
-    usage = sa.alias(usage, name='usage')
+    usage = usage.subquery(name='usage')
 
     inv_join = sql.join(
         _RP_TBL, _INV_TBL,
diff --git a/placement/objects/research_context.py b/placement/objects/research_context.py
index e3e45e58e..767ce0a24 100644
--- a/placement/objects/research_context.py
+++ b/placement/objects/research_context.py
@@ -422,7 +422,7 @@ def _usage_select(rc_ids):
     usage = usage.where(_ALLOC_TBL.c.resource_class_id.in_(rc_ids))
     usage = usage.group_by(_ALLOC_TBL.c.resource_provider_id,
                            _ALLOC_TBL.c.resource_class_id)
-    return sa.alias(usage, name='usage')
+    return usage.subquery(name='usage')
 
 
 def _capacity_check_clause(amount, usage, inv_tbl=_INV_TBL):
@@ -1350,16 +1350,14 @@ def get_usages_by_provider_trees(ctx, root_ids):
                 _RP_TBL.c.root_provider_id.in_(sa.bindparam(
                     'root_ids', expanding=True)))
     )
-    usage = sa.alias(
-        sa.select([
-            _ALLOC_TBL.c.resource_provider_id,
-            _ALLOC_TBL.c.resource_class_id,
-            sql.func.sum(_ALLOC_TBL.c.used).label('used'),
-        ]).select_from(derived_alloc_to_rp).group_by(
-            _ALLOC_TBL.c.resource_provider_id,
-            _ALLOC_TBL.c.resource_class_id
-        ),
-        name='usage')
+    usage = sa.select([
+        _ALLOC_TBL.c.resource_provider_id,
+        _ALLOC_TBL.c.resource_class_id,
+        sql.func.sum(_ALLOC_TBL.c.used).label('used'),
+    ]).select_from(derived_alloc_to_rp).group_by(
+        _ALLOC_TBL.c.resource_provider_id,
+        _ALLOC_TBL.c.resource_class_id
+    ).subquery(name='usage')
     # Build a join between the resource providers and inventories table
     rpt_inv_join = sa.outerjoin(rpt, inv,
                                 rpt.c.id == inv.c.resource_provider_id)
diff --git a/placement/tests/functional/fixtures/capture.py b/placement/tests/functional/fixtures/capture.py
index 637c96212..89934ba9d 100644
--- a/placement/tests/functional/fixtures/capture.py
+++ b/placement/tests/functional/fixtures/capture.py
@@ -17,6 +17,7 @@ import warnings
 
 import fixtures
 from oslotest import log
+from sqlalchemy import exc as sqla_exc
 
 
 class NullHandler(logging.Handler):
@@ -69,13 +70,30 @@ class WarningsFixture(fixtures.Fixture):
     def setUp(self):
         super(WarningsFixture, self).setUp()
 
+        warnings.simplefilter("once", DeprecationWarning)
+
         # Ignore policy scope warnings.
-        warnings.filterwarnings('ignore',
-                                message="Policy .* failed scope check",
-                                category=UserWarning)
+        warnings.filterwarnings(
+            'ignore',
+            message="Policy .* failed scope check",
+            category=UserWarning)
+
         # The UUIDFields emits a warning if the value is not a  valid UUID.
         # Let's escalate that to an exception in the test to prevent adding
         # violations.
         warnings.filterwarnings('error', message=".*invalid UUID.*")
 
+        # Prevent us introducing unmapped columns
+        warnings.filterwarnings(
+            'error',
+            message='Evaluating non-mapped column expression',
+            category=sqla_exc.SAWarning)
+
+        # TODO(stephenfin): Remove once we're using sqlalchemy 2.0 which should
+        # remove this functionality entirely
+        warnings.filterwarnings(
+            'error',
+            message='Implicit coercion of SELECT and textual SELECT .*',
+            category=sqla_exc.SADeprecationWarning)
+
         self.addCleanup(warnings.resetwarnings)
diff --git a/requirements.txt b/requirements.txt
index 6e6b9ce9c..500e447ec 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,7 +3,7 @@
 # process, which may cause wedges in the gate later.
 
 pbr>=3.1.1 # Apache-2.0
-SQLAlchemy>=1.2.19 # MIT
+SQLAlchemy>=1.4.0 # MIT
 keystonemiddleware>=4.18.0 # Apache-2.0
 Routes>=2.3.1 # MIT
 WebOb>=1.8.2 # MIT
@@ -16,7 +16,7 @@ oslo.context>=2.22.0 # Apache-2.0
 oslo.log>=4.3.0 # Apache-2.0
 oslo.serialization>=2.25.0 # Apache-2.0
 oslo.utils>=4.5.0 # Apache-2.0
-oslo.db>=4.40.0 # Apache-2.0
+oslo.db>=8.6.0 # Apache-2.0
 oslo.policy>=3.7.0 # Apache-2.0
 oslo.middleware>=3.31.0 # Apache-2.0
 oslo.upgradecheck>=1.3.0 # Apache-2.0