diff --git a/types/int_test.go b/types/int_test.go
new file mode 100644
index 00000000..d8a0506c
--- /dev/null
+++ b/types/int_test.go
@@ -0,0 +1,87 @@
+package types
+
+import (
+	"database/sql"
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func TestInt_MarshalJSON(t *testing.T) {
+	subtests := []struct {
+		name   string
+		input  sql.NullInt64
+		output string
+	}{
+		{"null", sql.NullInt64{}, `null`},
+		{"invalid", sql.NullInt64{Int64: 42}, `null`},
+		{"zero", sql.NullInt64{Int64: 0, Valid: true}, `0`},
+		{"negative", sql.NullInt64{Int64: -1, Valid: true}, `-1`},
+	}
+
+	for _, st := range subtests {
+		t.Run(st.name, func(t *testing.T) {
+			actual, err := Int{st.input}.MarshalJSON()
+
+			require.NoError(t, err)
+			require.Equal(t, st.output, string(actual))
+		})
+	}
+}
+
+func TestInt_UnmarshalText(t *testing.T) {
+	subtests := []struct {
+		name   string
+		input  string
+		output sql.NullInt64
+		error  bool
+	}{
+		{"empty", "", sql.NullInt64{}, true},
+		{"2p64", "18446744073709551616", sql.NullInt64{}, true},
+		{"float", "0.0", sql.NullInt64{}, true},
+		{"zero", "0", sql.NullInt64{Int64: 0, Valid: true}, false},
+		{"negative", "-1", sql.NullInt64{Int64: -1, Valid: true}, false},
+		{"2p62", "4611686018427387904", sql.NullInt64{Int64: 1 << 62, Valid: true}, false},
+	}
+
+	for _, st := range subtests {
+		t.Run(st.name, func(t *testing.T) {
+			var actual Int
+			if err := actual.UnmarshalText([]byte(st.input)); st.error {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+				require.Equal(t, Int{NullInt64: st.output}, actual)
+			}
+		})
+	}
+}
+
+func TestInt_UnmarshalJSON(t *testing.T) {
+	subtests := []struct {
+		name   string
+		input  string
+		output sql.NullInt64
+		error  bool
+	}{
+		{"null", `null`, sql.NullInt64{}, false},
+		{"bool", `false`, sql.NullInt64{}, true},
+		{"2p64", `18446744073709551616`, sql.NullInt64{}, true},
+		{"float", `0.0`, sql.NullInt64{}, true},
+		{"string", `"0"`, sql.NullInt64{}, true},
+		{"zero", `0`, sql.NullInt64{Int64: 0, Valid: true}, false},
+		{"negative", `-1`, sql.NullInt64{Int64: -1, Valid: true}, false},
+		{"2p62", `4611686018427387904`, sql.NullInt64{Int64: 1 << 62, Valid: true}, false},
+	}
+
+	for _, st := range subtests {
+		t.Run(st.name, func(t *testing.T) {
+			var actual Int
+			if err := actual.UnmarshalJSON([]byte(st.input)); st.error {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+				require.Equal(t, Int{NullInt64: st.output}, actual)
+			}
+		})
+	}
+}