diff --git a/integration/integration_test.go b/integration/integration_test.go
index 02f5de3..2ad1729 100644
--- a/integration/integration_test.go
+++ b/integration/integration_test.go
@@ -1,4 +1,3 @@
-// integration/integration_test.go
 package integration
 
 import (
@@ -13,35 +12,35 @@ import (
 	"gotest.tools/v3/icmd"
 )
 
-// Skip encoding tests for these extensions (same semantics as your original)
-var encodeOnly = map[string]bool{
-	"heic": true,
-	"heif": true,
-	"psd":  true,
-	"svg":  true,
-}
-
-const (
-	fixturesDir = "images"       // integration/images/
-	exampleJPEG = "example.jpeg" // integration/example.jpeg (256x256)
+var (
+	executable = "ffwebp"
+	encodeOnly = map[string]bool{
+		"heic": true,
+		"heif": true,
+		"psd":  true,
+		"svg":  true,
+	}
 )
 
-var ffwebpBin string // set in TestMain
+const (
+	fixturesDir = "images"
+	exampleJPEG = "example.jpeg"
+)
 
 func TestMain(m *testing.M) {
-	// Build the CLI once with -tags=full into a temp dir, reusing it across tests.
 	tmp, err := os.MkdirTemp("", "ffwebp-bin-*")
 	if err != nil {
-		fmt.Fprintln(os.Stderr, "mktemp:", err)
+		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
 	}
+
 	defer os.RemoveAll(tmp)
 
-	exe := "ffwebp"
 	if runtime.GOOS == "windows" {
-		exe += ".exe"
+		executable += ".exe"
 	}
-	ffwebpBin = filepath.Join(tmp, exe)
+
+	executable = filepath.Join(tmp, executable)
 
 	root, err := findRepoRoot()
 	if err != nil {
@@ -49,9 +48,10 @@ func TestMain(m *testing.M) {
 		os.Exit(1)
 	}
 
-	// Build from repo root so relative paths to ./cmd/ffwebp resolve.
-	build := icmd.Command("go", "build", "-tags=full", "-o", ffwebpBin, "./cmd/ffwebp")
+	build := icmd.Command("go", "build", "-tags=full", "-o", executable, "./cmd/ffwebp")
+
 	build.Dir = root
+
 	res := icmd.RunCmd(build)
 	if res.ExitCode != 0 {
 		fmt.Fprintln(os.Stderr, res.Combined())
@@ -62,7 +62,6 @@ func TestMain(m *testing.M) {
 }
 
 func TestCLI_CodecDecodeAndRoundTrip(t *testing.T) {
-	// Discover input samples: integration/images/image.<ext>
 	entries, err := os.ReadDir(fixturesDir)
 	if err != nil {
 		t.Fatalf("read %s: %v", fixturesDir, err)
@@ -72,38 +71,41 @@ func TestCLI_CodecDecodeAndRoundTrip(t *testing.T) {
 		if e.IsDir() {
 			continue
 		}
+
 		inPath := filepath.Join(fixturesDir, e.Name())
 		ext := strings.TrimPrefix(filepath.Ext(e.Name()), ".")
 
-		// 1) <codec> -> jpeg
+		// test going from codec to jpeg
 		t.Run("decode_"+ext, func(t *testing.T) {
 			tmp := t.TempDir()
+
 			out := filepath.Join(tmp, "decoded.jpeg")
 
-			run(t, icmd.Command(ffwebpBin, "-s", "-i", inPath, "-o", out))
+			run(t, icmd.Command(executable, "-s", "-i", inPath, "-o", out))
 
 			w, h := jpegSize(t, out)
 			if w == 0 || h == 0 {
-				t.Fatalf("decoded JPEG has invalid size: %dx%d", w, h)
+				t.Fatalf("decoded JPEG has no size: %dx%d", w, h)
 			}
 		})
 
-		// 2) jpeg -> <codec> -> jpeg (dimension stays 256x256), unless encodeOnly
+		// test going from jpeg to codec then back to jpeg
 		if encodeOnly[ext] {
 			continue
 		}
 
 		t.Run("encode_"+ext, func(t *testing.T) {
 			tmp := t.TempDir()
+
 			mid := filepath.Join(tmp, "encoded."+ext)
 			back := filepath.Join(tmp, "roundtrip.jpeg")
 
-			run(t, icmd.Command(ffwebpBin, "-s", "-i", exampleJPEG, "-o", mid))
-			run(t, icmd.Command(ffwebpBin, "-s", "-i", mid, "-o", back))
+			run(t, icmd.Command(executable, "-s", "-i", exampleJPEG, "-o", mid))
+			run(t, icmd.Command(executable, "-s", "-i", mid, "-o", back))
 
 			w, h := jpegSize(t, back)
 			if w != 256 || h != 256 {
-				t.Fatalf("roundtrip dimension mismatch: got %dx%d, want 256x256", w, h)
+				t.Fatalf("dimension mismatch: got %dx%d, want 256x256", w, h)
 			}
 		})
 	}
@@ -111,40 +113,47 @@ func TestCLI_CodecDecodeAndRoundTrip(t *testing.T) {
 
 func run(t *testing.T, cmd icmd.Cmd) {
 	t.Helper()
+
 	res := icmd.RunCmd(cmd)
-	// On failure, icmd prints the command line + stdout/stderr, which is handy.
+
 	res.Assert(t, icmd.Success)
 }
 
 func jpegSize(t *testing.T, path string) (int, int) {
 	t.Helper()
-	f, err := os.Open(path)
+
+	f, err := os.OpenFile(path, os.O_RDONLY, 0)
 	if err != nil {
 		t.Fatalf("open %s: %v", path, err)
 	}
+
 	defer f.Close()
 
 	cfg, err := jpeg.DecodeConfig(f)
 	if err != nil {
 		t.Fatalf("decode jpeg config %s: %v", path, err)
 	}
+
 	return cfg.Width, cfg.Height
 }
 
 func findRepoRoot() (string, error) {
-	// Walk up to find go.mod so we can run `go build ./cmd/ffwebp` reliably.
 	dir, err := os.Getwd()
 	if err != nil {
 		return "", err
 	}
+
 	for {
 		if _, err := os.Stat(filepath.Join(dir, "go.mod")); err == nil {
 			return dir, nil
 		}
+
 		parent := filepath.Dir(dir)
+
 		if parent == dir {
 			return "", fmt.Errorf("could not locate go.mod starting from %s", dir)
 		}
+
 		dir = parent
 	}
 }