diff --git a/localtime.go b/localtime.go
index 6555a10..f271bef 100644
--- a/localtime.go
+++ b/localtime.go
@@ -23,6 +23,7 @@
 //
 // Because they lack location information, these types do not represent unique
 // moments or intervals of time. Use time.Time for that purpose.
+
 package toml
 
 import (
diff --git a/parser_test.go b/parser_test.go
index bdae78a..e4b82a3 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -155,12 +155,14 @@ func TestParser_AST_Numbers(t *testing.T) {
 	}
 }
 
-type astRoot []astNode
-type astNode struct {
-	Kind     ast.Kind
-	Data     []byte
-	Children []astNode
-}
+type (
+	astRoot []astNode
+	astNode struct {
+		Kind     ast.Kind
+		Data     []byte
+		Children []astNode
+	}
+)
 
 func compareAST(t *testing.T, expected astRoot, actual *ast.Root) {
 	it := actual.Iterator()
@@ -168,6 +170,7 @@ func compareAST(t *testing.T, expected astRoot, actual *ast.Root) {
 }
 
 func compareNode(t *testing.T, e astNode, n ast.Node) {
+	t.Helper()
 	require.Equal(t, e.Kind, n.Kind)
 	require.Equal(t, e.Data, n.Data)
 
@@ -175,6 +178,7 @@ func compareNode(t *testing.T, e astNode, n ast.Node) {
 }
 
 func compareIterator(t *testing.T, expected []astNode, actual ast.Iterator) {
+	t.Helper()
 	idx := 0
 
 	for actual.Next() {
diff --git a/toml.abnf b/toml.abnf
index 5655ed5..473f374 100644
--- a/toml.abnf
+++ b/toml.abnf
@@ -59,6 +59,7 @@ val = string / boolean / array / inline-table / date-time / float / integer
 ;; String
 
 string = ml-basic-string / basic-string / ml-literal-string / literal-string
+
 ;; Basic String
 
 basic-string = quotation-mark *basic-char quotation-mark
diff --git a/unmarshaler_test.go b/unmarshaler_test.go
index 8d742f0..4cda0de 100644
--- a/unmarshaler_test.go
+++ b/unmarshaler_test.go
@@ -132,6 +132,7 @@ func TestUnmarshal_Floats(t *testing.T) {
 			desc:  "nan",
 			input: `nan`,
 			testFn: func(t *testing.T, v float64) {
+				t.Helper()
 				assert.True(t, math.IsNaN(v))
 			},
 		},
@@ -139,6 +140,7 @@ func TestUnmarshal_Floats(t *testing.T) {
 			desc:  "nan negative",
 			input: `-nan`,
 			testFn: func(t *testing.T, v float64) {
+				t.Helper()
 				assert.True(t, math.IsNaN(v))
 			},
 		},
@@ -146,6 +148,7 @@ func TestUnmarshal_Floats(t *testing.T) {
 			desc:  "nan positive",
 			input: `+nan`,
 			testFn: func(t *testing.T, v float64) {
+				t.Helper()
 				assert.True(t, math.IsNaN(v))
 			},
 		},
@@ -759,8 +762,10 @@ func TestIssue484(t *testing.T) {
 	}, cfg)
 }
 
-type Map458 map[string]interface{}
-type Slice458 []interface{}
+type (
+	Map458   map[string]interface{}
+	Slice458 []interface{}
+)
 
 func (m Map458) A(s string) Slice458 {
 	return m[s].([]interface{})
@@ -779,7 +784,8 @@ version = "0.1.0"`)
 		map[string]interface{}{
 			"dependencies": []interface{}{"regex"},
 			"name":         "decode",
-			"version":      "0.1.0"},
+			"version":      "0.1.0",
+		},
 	}
 	assert.Equal(t, expected, a)
 }
@@ -790,7 +796,7 @@ func TestIssue252(t *testing.T) {
 		Val2 string `toml:"val2"`
 	}
 
-	var configFile = []byte(
+	configFile := []byte(
 		`
 val1 = "test1"
 `)
@@ -940,7 +946,7 @@ func TestIssue508(t *testing.T) {
 		head
 	}
 
-	var b = []byte(`title = "This is a title"`)
+	b := []byte(`title = "This is a title"`)
 
 	t1 := text{}
 	err := toml.Unmarshal(b, &t1)