diff --git a/django/db/models/base.py b/django/db/models/base.py
index b58e7e3e52..8d7cbdd32d 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -1801,7 +1801,7 @@ class Model(AltersData, metaclass=ModelBase):
         meta = cls._meta
         pk = meta.pk
 
-        if not isinstance(pk, CompositePrimaryKey):
+        if meta.proxy or not isinstance(pk, CompositePrimaryKey):
             return errors
 
         seen_columns = defaultdict(list)
diff --git a/docs/releases/5.2.8.txt b/docs/releases/5.2.8.txt
index a75db9cbc8..62cb32f55c 100644
--- a/docs/releases/5.2.8.txt
+++ b/docs/releases/5.2.8.txt
@@ -16,3 +16,6 @@ Bugfixes
 * Fixed a bug in Django 5.2 where ``QuerySet.first()`` and ``QuerySet.last()``
   raised an error on querysets performing aggregation that selected all fields
   of a composite primary key.
+
+* Fixed a bug in Django 5.2 where proxy models having a ``CompositePrimaryKey``
+  incorrectly raised a ``models.E042`` system check error.
diff --git a/tests/composite_pk/test_checks.py b/tests/composite_pk/test_checks.py
index c33f2ee2eb..21796aa871 100644
--- a/tests/composite_pk/test_checks.py
+++ b/tests/composite_pk/test_checks.py
@@ -268,3 +268,38 @@ class CompositePKChecksTests(TestCase):
                 ),
             ],
         )
+
+    def test_proxy_model_can_subclass_model_with_composite_pk(self):
+        class Foo(models.Model):
+            pk = models.CompositePrimaryKey("a", "b")
+            a = models.SmallIntegerField()
+            b = models.SmallIntegerField()
+
+        class Bar(Foo):
+            class Meta:
+                proxy = True
+
+        self.assertEqual(Foo.check(databases=self.databases), [])
+        self.assertEqual(Bar.check(databases=self.databases), [])
+
+    def test_proxy_model_does_not_check_superclass_composite_pk_errors(self):
+        class Foo(models.Model):
+            pk = models.CompositePrimaryKey("a", "b")
+            a = models.SmallIntegerField()
+
+        class Bar(Foo):
+            class Meta:
+                proxy = True
+
+        self.assertEqual(
+            Foo.check(databases=self.databases),
+            [
+                checks.Error(
+                    "'b' cannot be included in the composite primary key.",
+                    hint="'b' is not a valid field.",
+                    obj=Foo,
+                    id="models.E042",
+                ),
+            ],
+        )
+        self.assertEqual(Bar.check(databases=self.databases), [])