diff --git a/internal/log/formatter.go b/internal/log/formatter.go
index 4db6913c..db067d12 100644
--- a/internal/log/formatter.go
+++ b/internal/log/formatter.go
@@ -128,11 +128,11 @@ func (f *Formatter) Format(entry *logrus.Entry) ([]byte, error) {
 
 func trimFilename(s string) string {
 	const sub = "pg_timetable/internal/"
-	idx := strings.Index(s, sub)
-	if idx == -1 {
+	_, after, ok := strings.Cut(s, sub)
+	if !ok {
 		return s
 	}
-	return s[idx+len(sub):]
+	return after
 }
 
 func (f *Formatter) writeCaller(b *bytes.Buffer, entry *logrus.Entry) {
diff --git a/internal/pgengine/access_test.go b/internal/pgengine/access_test.go
index 77d8209f..825c31c9 100644
--- a/internal/pgengine/access_test.go
+++ b/internal/pgengine/access_test.go
@@ -67,7 +67,7 @@ func TestSelectChains(t *testing.T) {
 	pge := pgengine.NewDB(mockPool, "pgengine_unit_test")
 	defer mockPool.Close()
 
-	for i := 0; i < 3; i++ {
+	for range 3 {
 		mockPool.ExpectQuery("SELECT.+chain_id").WithArgs(pgxmock.AnyArg()).WillReturnError(errors.New("error"))
 		mockPool.ExpectQuery("SELECT.+chain_id").WithArgs(pgxmock.AnyArg()).WillReturnRows(pgxmock.NewRows([]string{"foo"}).AddRow("baz"))
 	}
diff --git a/internal/pgengine/bootstrap_test.go b/internal/pgengine/bootstrap_test.go
index 461a7231..02cef91d 100644
--- a/internal/pgengine/bootstrap_test.go
+++ b/internal/pgengine/bootstrap_test.go
@@ -50,7 +50,7 @@ func TestExecuteSchemaScripts(t *testing.T) {
 		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 		defer cancel()
 		mockPool.ExpectQuery("SELECT EXISTS").WillReturnRows(pgxmock.NewRows([]string{"exists"}).AddRow(false))
-		for i := 0; i < 5; i++ {
+		for range 5 {
 			mockPool.ExpectExec(".*").WillReturnResult(pgxmock.NewResult("EXECUTE", 1))
 		}
 		assert.NoError(t, mockpge.ExecuteSchemaScripts(ctx))
diff --git a/internal/pgengine/log_hook_test.go b/internal/pgengine/log_hook_test.go
index 67be8cea..dad456c2 100644
--- a/internal/pgengine/log_hook_test.go
+++ b/internal/pgengine/log_hook_test.go
@@ -59,8 +59,7 @@ func TestCancelledContext(t *testing.T) {
 }
 
 func TestFireError(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := t.Context()
 	h := NewHook(ctx, &PgEngine{}, "debug")
 	err := errors.New("fire error")
 	go func() { h.lastError <- err }()
diff --git a/internal/scheduler/shell_test.go b/internal/scheduler/shell_test.go
index 8804619f..5b6675d2 100644
--- a/internal/scheduler/shell_test.go
+++ b/internal/scheduler/shell_test.go
@@ -24,9 +24,9 @@ type testCommander struct{}
 // overwrite CombinedOutput function of os/exec so only parameter syntax and return codes are checked...
 func (c testCommander) CombinedOutput(_ context.Context, command string, args ...string) ([]byte, error) {
 	if strings.HasPrefix(command, "ping") {
-		return []byte(fmt.Sprint(command, args)), nil
+		return fmt.Append(nil, command, args), nil
 	}
-	return []byte(fmt.Sprintf("Command %s not found", command)), &exec.Error{Name: command, Err: exec.ErrNotFound}
+	return fmt.Appendf(nil, "Command %s not found", command), &exec.Error{Name: command, Err: exec.ErrNotFound}
 }
 
 func TestShellCommandDuration(t *testing.T) {
diff --git a/internal/tasks/files_test.go b/internal/tasks/files_test.go
index f344a820..b2c5714a 100644
--- a/internal/tasks/files_test.go
+++ b/internal/tasks/files_test.go
@@ -19,7 +19,7 @@ var ts = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http
 	}
 	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment;filename=\"%s\"", "test.txt"))
 	bw := bufio.NewWriterSize(w, 4096)
-	for i := 0; i < 4096; i++ {
+	for i := range 4096 {
 		_, _ = bw.Write([]byte{byte(i)})
 	}
 	_ = bw.Flush()