diff --git a/src/test/normalize_test.ts b/src/test/normalize_test.ts
index 93b4c3a..fbc36ba 100644
--- a/src/test/normalize_test.ts
+++ b/src/test/normalize_test.ts
@@ -1,11 +1,15 @@
 import {normalizeSpawnCommand} from '../normalize.js';
 import {describe, test, expect} from 'vitest';
 import os from 'node:os';
+import path from 'node:path';
+import {fileURLToPath} from 'node:url';
 
 const isWindows = os.platform() === 'win32';
-const baseWindowsOptions = {
-  env: process.env
-};
+const fixturesPath = path.join(
+  path.dirname(fileURLToPath(import.meta.url)),
+  '../test/fixtures'
+);
+const cwd = process.cwd();
 
 describe('normalizeSpawnCommand', () => {
   test('return from arguments if `shell` option is `true`', () => {
@@ -14,40 +18,75 @@ describe('normalizeSpawnCommand', () => {
       args: ['-v'],
       options: {shell: true}
     });
+    expect(
+      normalizeSpawnCommand('nonexistent', ['somearg'], {shell: true})
+    ).toEqual({
+      command: 'nonexistent',
+      args: ['somearg'],
+      options: {shell: true}
+    });
   });
 
   describe.runIf(isWindows)('windows only', () => {
-    test('just return the same input if resolved', () => {
-      const normalized = normalizeSpawnCommand(
-        'node',
-        ['-v'],
-        baseWindowsOptions
-      );
+    test('returns input as-is if command was resolved', () => {
+      const normalized = normalizeSpawnCommand('node', ['-v'], {});
 
-      expect(normalized.command).toBe('node');
-      expect(normalized.args).toEqual(['-v']);
+      expect(normalized).toEqual({
+        command: 'node',
+        args: ['-v'],
+        options: {}
+      });
     });
 
-    test('use shell if command are not resolved/available', () => {
-      const normalized = normalizeSpawnCommand(
-        'notexist',
-        ['hi'],
-        baseWindowsOptions
+    test('use shell if command could not be resolved', () => {
+      const normalized = normalizeSpawnCommand('nonexistent', ['hi'], {});
+
+      expect(normalized).toEqual({
+        command: 'cmd.exe',
+        args: ['/d', '/s', '/c', '"nonexistent ^"hi^""'],
+        options: {windowsVerbatimArguments: true}
+      });
+    });
+
+    test('handles relative commands', () => {
+      const relativePath = path.relative(
+        cwd,
+        path.join(fixturesPath, 'hello_world.cmd')
       );
+      const normalized = normalizeSpawnCommand(relativePath, []);
+      expect(normalized).toEqual({
+        command: 'cmd.exe',
+        args: ['/d', '/s', '/c', `"${relativePath}"`],
+        options: {windowsVerbatimArguments: true}
+      });
+    });
 
-      expect(normalized.command.endsWith('cmd.exe')).ok;
-      expect(normalized.args).toEqual(['/d', '/s', '/c', '"notexist ^"hi^""']);
-      expect(normalized.options.windowsVerbatimArguments).toBe(true);
+    test('handles relative commands without extension', () => {
+      const relativePath = path.relative(
+        cwd,
+        path.join(fixturesPath, 'hello_world')
+      );
+      const normalized = normalizeSpawnCommand(relativePath, []);
+      expect(normalized).toEqual({
+        command: 'cmd.exe',
+        args: ['/d', '/s', '/c', `"${relativePath}"`],
+        options: {windowsVerbatimArguments: true}
+      });
     });
   });
 
   describe.runIf(!isWindows)('unix only', () => {
-    test('return from arguments', () => {
+    test('returns command as-is', () => {
       expect(normalizeSpawnCommand('node', ['-v'])).toEqual({
         command: 'node',
         args: ['-v'],
         options: {}
       });
+      expect(normalizeSpawnCommand('nonexistent', ['somearg'])).toEqual({
+        command: 'nonexistent',
+        args: ['somearg'],
+        options: {}
+      });
     });
   });
 });
diff --git a/test/fixtures/hello_world.cmd b/test/fixtures/hello_world.cmd
new file mode 100644
index 0000000..8fbf7fa
--- /dev/null
+++ b/test/fixtures/hello_world.cmd
@@ -0,0 +1 @@
+echo Hello, World!