diff --git a/cmd/zenity/main.go b/cmd/zenity/main.go
index 71640ad..a274567 100644
--- a/cmd/zenity/main.go
+++ b/cmd/zenity/main.go
@@ -374,14 +374,17 @@ func egestPaths(paths []string, err error) ([]string, error) {
 	return paths, err
 }
 
+// FileFilters is internal.
 type FileFilters struct {
 	zenity.FileFilters
 }
 
+// String is internal.
 func (f *FileFilters) String() string {
 	return "zenity.FileFilters"
 }
 
+// Set is internal.
 func (f *FileFilters) Set(s string) error {
 	var filter zenity.FileFilter
 
diff --git a/internal/zenutil/color.go b/internal/zenutil/color.go
index 7e90ed8..366de9f 100644
--- a/internal/zenutil/color.go
+++ b/internal/zenutil/color.go
@@ -8,6 +8,7 @@ import (
 	"golang.org/x/image/colornames"
 )
 
+// ParseColor is internal.
 func ParseColor(s string) color.Color {
 	if len(s) == 4 || len(s) == 5 {
 		c := color.NRGBA{A: 0xf}
@@ -46,6 +47,7 @@ func ParseColor(s string) color.Color {
 	return nil
 }
 
+// UnparseColor is internal.
 func UnparseColor(c color.Color) string {
 	n := color.NRGBAModel.Convert(c).(color.NRGBA)
 	if n.A == 255 {
diff --git a/internal/zenutil/env_darwin.go b/internal/zenutil/env_darwin.go
index 0251d26..fd9fdda 100644
--- a/internal/zenutil/env_darwin.go
+++ b/internal/zenutil/env_darwin.go
@@ -1,7 +1,13 @@
 package zenutil
 
-const LineBreak = "\n"
+// These are internal.
+const (
+	LineBreak = "\n"
+)
 
-var Command bool
-var Timeout int
-var Separator = "\x00"
+// These are internal.
+var (
+	Command   bool
+	Timeout   int
+	Separator = "\x00"
+)
diff --git a/internal/zenutil/env_unix.go b/internal/zenutil/env_unix.go
index e2bdade..154e71e 100644
--- a/internal/zenutil/env_unix.go
+++ b/internal/zenutil/env_unix.go
@@ -3,8 +3,14 @@
 // Package zenutil is internal. DO NOT USE.
 package zenutil
 
-const LineBreak = "\n"
+// These are internal.
+const (
+	LineBreak = "\n"
+)
 
-var Command bool
-var Timeout int
-var Separator = "\x1e"
+// These are internal.
+var (
+	Command   bool
+	Timeout   int
+	Separator = "\x1e"
+)
diff --git a/internal/zenutil/env_windows.go b/internal/zenutil/env_windows.go
index 6bd4c22..ee0957a 100644
--- a/internal/zenutil/env_windows.go
+++ b/internal/zenutil/env_windows.go
@@ -1,7 +1,13 @@
 package zenutil
 
-const LineBreak = "\r\n"
+// These are internal.
+const (
+	LineBreak = "\r\n"
+)
 
-var Command bool
-var Timeout int
-var Separator string
+// These are internal.
+var (
+	Command   bool
+	Timeout   int
+	Separator string
+)
diff --git a/internal/zenutil/run_darwin.go b/internal/zenutil/run_darwin.go
index 7d02df4..0c24522 100644
--- a/internal/zenutil/run_darwin.go
+++ b/internal/zenutil/run_darwin.go
@@ -8,6 +8,7 @@ import (
 	"syscall"
 )
 
+// Run is internal.
 func Run(ctx context.Context, script string, data interface{}) ([]byte, error) {
 	var buf strings.Builder
 
diff --git a/internal/zenutil/run_unix.go b/internal/zenutil/run_unix.go
index 43c7f92..c378a6f 100644
--- a/internal/zenutil/run_unix.go
+++ b/internal/zenutil/run_unix.go
@@ -22,6 +22,7 @@ func init() {
 	tool = "zenity"
 }
 
+// Run is internal.
 func Run(ctx context.Context, args []string) ([]byte, error) {
 	if Command && path != "" {
 		if Timeout > 0 {