diff --git a/internal/dbmodel/model_test.go b/internal/dbmodel/model_test.go
index 923a010a5..195c1fda1 100644
--- a/internal/dbmodel/model_test.go
+++ b/internal/dbmodel/model_test.go
@@ -57,7 +57,7 @@ func TestRecreateDeletedModel(t *testing.T) {
 		CloudRegion:     cl.Regions[0],
 		CloudCredential: cred,
 	}
-	c.Check(db.Create(&m2).Error, qt.ErrorMatches, `.*violates unique constraint "models_controller_id_owner_identity_name_name_key".*`)
+	c.Check(db.Create(&m2).Error, qt.ErrorMatches, `.*violates unique constraint "unique_model_names".*`)
 
 	c.Assert(db.Delete(&m1).Error, qt.IsNil)
 	c.Check(db.First(&m1).Error, qt.Equals, gorm.ErrRecordNotFound)
@@ -187,7 +187,7 @@ func TestModelUniqueConstraint(t *testing.T) {
 			Level: "unsupported",
 		},
 	}
-	c.Assert(db.Create(&m2).Error, qt.IsNil)
+	c.Assert(db.Create(&m2).Error, qt.ErrorMatches, `ERROR: duplicate key value violates unique constraint .*`)
 
 	m3 := dbmodel.Model{
 		UUID: sql.NullString{
diff --git a/internal/dbmodel/sql/postgres/1_10.sql b/internal/dbmodel/sql/postgres/1_10.sql
new file mode 100644
index 000000000..453fb7460
--- /dev/null
+++ b/internal/dbmodel/sql/postgres/1_10.sql
@@ -0,0 +1,6 @@
+-- 1_10.sql is a migration that enforces a stricter uniqueness 
+-- constraint on model names.
+ALTER TABLE models DROP CONSTRAINT models_controller_id_owner_identity_name_name_key;
+ALTER TABLE models ADD CONSTRAINT unique_model_names UNIQUE(owner_identity_name, name);
+
+UPDATE versions SET major=1, minor=10 WHERE component='jimmdb';
diff --git a/internal/dbmodel/version.go b/internal/dbmodel/version.go
index 1649904f4..f5229fc18 100644
--- a/internal/dbmodel/version.go
+++ b/internal/dbmodel/version.go
@@ -20,7 +20,7 @@ const (
 	// Minor is the minor version of the model described in the dbmodel
 	// package. It should be incremented for any change made to the
 	// database model from database model in a released JIMM.
-	Minor = 9
+	Minor = 10
 )
 
 type Version struct {
diff --git a/internal/jujuapi/modelmanager_test.go b/internal/jujuapi/modelmanager_test.go
index 3a5bfb87c..e937d829e 100644
--- a/internal/jujuapi/modelmanager_test.go
+++ b/internal/jujuapi/modelmanager_test.go
@@ -917,6 +917,24 @@ func (s *modelManagerSuite) TestCreateModel(c *gc.C) {
 	}
 }
 
+func (s *modelManagerSuite) TestCreateDuplicateModelsFails(c *gc.C) {
+	conn := s.open(c, nil, "bob")
+	defer conn.Close()
+	createModel := func(mi jujuparams.ModelInfo) error {
+		return conn.APICall("ModelManager", 9, "", "CreateModel", jujuparams.ModelCreateArgs{
+			Name:               "my-model",
+			OwnerTag:           names.NewUserTag("bob@canonical.com").String(),
+			CloudTag:           names.NewCloudTag(jimmtest.TestCloudName).String(),
+			CloudCredentialTag: "cloudcred-" + jimmtest.TestCloudName + "_bob@canonical.com_cred",
+		}, &mi)
+	}
+	var mi jujuparams.ModelInfo
+	err := createModel(mi)
+	c.Assert(err, gc.IsNil)
+	err = createModel(mi)
+	c.Assert(err, gc.ErrorMatches, `model bob@canonical\.com/my-model already exists \(already exists\)`)
+}
+
 func (s *modelManagerSuite) TestGrantAndRevokeModel(c *gc.C) {
 	conn := s.open(c, nil, "bob")
 	defer conn.Close()