diff --git a/api/api_integration_test.go b/api/api_integration_test.go
index 77683c49ac..d29529f334 100644
--- a/api/api_integration_test.go
+++ b/api/api_integration_test.go
@@ -152,6 +152,7 @@ func testPostgresDB(t testing.TB) (string, func()) {
 		if err != nil {
 			return err
 		}
+		defer db.Close()
 		return db.Ping()
 	}); err != nil {
 		t.Fatalf("postgresdb: could not connect: %s", err)
diff --git a/builtin/logical/mssql/backend_test.go b/builtin/logical/mssql/backend_test.go
index 88a05efd9c..438ee5f374 100644
--- a/builtin/logical/mssql/backend_test.go
+++ b/builtin/logical/mssql/backend_test.go
@@ -53,6 +53,7 @@ func prepareMSSQLTestContainer(t *testing.T) (func(), string) {
 		if err != nil {
 			return err
 		}
+		defer db.Close()
 		return db.Ping()
 	}); err != nil {
 		cleanup()
diff --git a/builtin/logical/mysql/backend_test.go b/builtin/logical/mysql/backend_test.go
index 23f0462709..5cd93b0391 100644
--- a/builtin/logical/mysql/backend_test.go
+++ b/builtin/logical/mysql/backend_test.go
@@ -47,6 +47,7 @@ func prepareTestContainer(t *testing.T) (func(), string) {
 		if err != nil {
 			return err
 		}
+		defer db.Close()
 		return db.Ping()
 	}); err != nil {
 		cleanup()
diff --git a/physical/cockroachdb/cockroachdb_test.go b/physical/cockroachdb/cockroachdb_test.go
index 043d60df85..140ac011ad 100644
--- a/physical/cockroachdb/cockroachdb_test.go
+++ b/physical/cockroachdb/cockroachdb_test.go
@@ -58,6 +58,7 @@ func prepareCockroachDBTestContainer(t *testing.T) (cleanup func(), retURL, tabl
 		if err != nil {
 			return err
 		}
+		defer db.Close()
 		_, err = db.Exec("CREATE DATABASE database")
 		return err
 	}); err != nil {
diff --git a/plugins/database/mongodb/mongodb_test.go b/plugins/database/mongodb/mongodb_test.go
index 9bb7d9d034..2374a95543 100644
--- a/plugins/database/mongodb/mongodb_test.go
+++ b/plugins/database/mongodb/mongodb_test.go
@@ -55,6 +55,7 @@ func prepareMongoDBTestContainer(t *testing.T) (cleanup func(), retURL string) {
 		if err != nil {
 			return err
 		}
+		defer session.Close()
 		session.SetSyncTimeout(1 * time.Minute)
 		session.SetSocketTimeout(1 * time.Minute)
 		return session.Ping()
diff --git a/plugins/database/mysql/mysql_test.go b/plugins/database/mysql/mysql_test.go
index 6a1ee9330c..8d3bcffa82 100644
--- a/plugins/database/mysql/mysql_test.go
+++ b/plugins/database/mysql/mysql_test.go
@@ -52,6 +52,7 @@ func prepareMySQLTestContainer(t *testing.T, legacy bool) (cleanup func(), retUR
 		if err != nil {
 			return err
 		}
+		defer db.Close()
 		return db.Ping()
 	}); err != nil {
 		cleanup()
diff --git a/plugins/database/postgresql/postgresql_test.go b/plugins/database/postgresql/postgresql_test.go
index 4b83060271..563df9d14e 100644
--- a/plugins/database/postgresql/postgresql_test.go
+++ b/plugins/database/postgresql/postgresql_test.go
@@ -50,6 +50,7 @@ func preparePostgresTestContainer(t *testing.T) (cleanup func(), retURL string)
 		if err != nil {
 			return err
 		}
+		defer db.Close()
 		return db.Ping()
 	}); err != nil {
 		t.Fatalf("Could not connect to PostgreSQL docker container: %s", err)