diff --git a/examples/fibonacci/fibonacci.q b/examples/fibonacci/fibonacci.q
deleted file mode 100644
index c188e38..0000000
--- a/examples/fibonacci/fibonacci.q
+++ /dev/null
@@ -1,19 +0,0 @@
-import sys
-
-main() {
-	let f = fibonacci(11)
-	sys.exit(f)
-}
-
-fibonacci(n Int) -> Int {
-	mut b = 0
-	mut c = 1
-
-	for 0..n {
-		let a = b
-		b = c
-		c = a + b
-	}
-
-	return b
-}
diff --git a/src/asm/Data.go b/src/asm/Data.go
index 9268c99..418a898 100644
--- a/src/asm/Data.go
+++ b/src/asm/Data.go
@@ -5,7 +5,8 @@ import "bytes"
 // Data represents the static read-only data.
 type Data []byte
 
-// Add adds the given bytes to the data block and returns the address relative to the start of the data section.
+// Add adds the given bytes to the data block if this sequence of bytes doesn't exist yet.
+// It returns the address relative to the start of the data section.
 func (data *Data) Add(block []byte) Address {
 	position := bytes.Index(*data, block)
 
diff --git a/main_test.go b/src/cli/Main_test.go
similarity index 62%
rename from main_test.go
rename to src/cli/Main_test.go
index ab4ac62..95fcf55 100644
--- a/main_test.go
+++ b/src/cli/Main_test.go
@@ -1,6 +1,7 @@
-package main_test
+package cli_test
 
 import (
+	"fmt"
 	"io"
 	"os"
 	"testing"
@@ -27,23 +28,17 @@ func TestCLI(t *testing.T) {
 		{[]string{"invalid"}, 2},
 		{[]string{"system"}, 0},
 		{[]string{"build", "non-existing-directory"}, 1},
-		{[]string{"build", "examples/hello/hello.q"}, 1},
-		{[]string{"build", "examples/hello", "--invalid"}, 2},
-		{[]string{"build", "examples/hello", "--dry"}, 0},
-		{[]string{"build", "examples/hello", "--dry", "--verbose"}, 0},
+		{[]string{"build", "../../examples/hello/hello.q"}, 1},
+		{[]string{"build", "../../examples/hello", "--invalid"}, 2},
+		{[]string{"build", "../../examples/hello", "--dry"}, 0},
+		{[]string{"build", "../../examples/hello", "--dry", "--verbose"}, 0},
 	}
 
 	for _, test := range tests {
 		t.Log(test.arguments)
+		directory, _ := os.Getwd()
+		fmt.Println(directory)
 		exitCode := cli.Main(test.arguments)
 		assert.Equal(t, exitCode, test.expectedExitCode)
 	}
 }
-
-func BenchmarkBuild(b *testing.B) {
-	args := []string{"build", "examples/hello", "--dry"}
-
-	for i := 0; i < b.N; i++ {
-		cli.Main(args)
-	}
-}
diff --git a/src/directory/Walk_test.go b/src/directory/Walk_test.go
new file mode 100644
index 0000000..a4fcda8
--- /dev/null
+++ b/src/directory/Walk_test.go
@@ -0,0 +1,19 @@
+package directory_test
+
+import (
+	"testing"
+
+	"git.akyoto.dev/cli/q/src/directory"
+	"git.akyoto.dev/go/assert"
+)
+
+func TestWalk(t *testing.T) {
+	var files []string
+
+	directory.Walk(".", func(file string) {
+		files = append(files, file)
+	})
+
+	assert.Contains(t, files, "Walk.go")
+	assert.Contains(t, files, "Walk_test.go")
+}
diff --git a/src/elf/ELF_test.go b/src/elf/ELF_test.go
new file mode 100644
index 0000000..45a9aa2
--- /dev/null
+++ b/src/elf/ELF_test.go
@@ -0,0 +1,13 @@
+package elf_test
+
+import (
+	"io"
+	"testing"
+
+	"git.akyoto.dev/cli/q/src/elf"
+)
+
+func TestELF(t *testing.T) {
+	exe := elf.New(nil, nil)
+	exe.Write(io.Discard)
+}