diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 88a0aa56..17399d15 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -45,6 +45,10 @@ jobs:
         with:
           fetch-depth: 0
           fetch-tags: true
+      - name: Setup deno
+        uses: denoland/setup-deno@v1
+        with:
+          deno-version: v1.x
       - name: Setup go
         uses: actions/setup-go@v5
         with:
diff --git a/internal/command/command_file.go b/internal/command/command_file.go
index 88b22a01..c345e2b4 100644
--- a/internal/command/command_file.go
+++ b/internal/command/command_file.go
@@ -13,10 +13,10 @@ import (
 type fileCommand struct {
 	internalCommand
 
+	logger *zap.Logger
+
 	scriptFile *os.File
 	tempDir    string
-
-	logger *zap.Logger
 }
 
 func (c *fileCommand) Start(ctx context.Context) error {
@@ -71,11 +71,23 @@ func (c *fileCommand) createTempDir() (err error) {
 }
 
 func (c *fileCommand) createScriptFile() (err error) {
-	c.scriptFile, err = os.CreateTemp(c.tempDir, "runme-script-*")
+	pattern := "runme-script-*"
+	if ext := c.scriptFileExt(); ext != "" {
+		pattern += "." + ext
+	}
+	c.scriptFile, err = os.CreateTemp(c.tempDir, pattern)
 	err = errors.WithMessage(err, "failed to create a temporary file for script execution")
 	return
 }
 
+func (c *fileCommand) scriptFileExt() string {
+	cfg := c.ProgramConfig()
+	if ext := cfg.GetFileExtension(); ext != "" {
+		return ext
+	}
+	return inferFileExtension(cfg.GetLanguageId())
+}
+
 func (c *fileCommand) removeTempDir() error {
 	if c.tempDir == "" {
 		return nil
@@ -90,3 +102,30 @@ func (c *fileCommand) writeScript(script string) error {
 	}
 	return errors.WithMessage(c.scriptFile.Close(), "failed to close the temporary file")
 }
+
+var fileExtensionByLanguageID = map[string]string{
+	"js":              "js",
+	"javascript":      "js",
+	"jsx":             "jsx",
+	"javascriptreact": "jsx",
+	"tsx":             "tsx",
+	"typescriptreact": "tsx",
+	"typescript":      "ts",
+	"ts":              "ts",
+	"sh":              "sh",
+	"bash":            "sh",
+	"ksh":             "sh",
+	"zsh":             "sh",
+	"fish":            "sh",
+	"powershell":      "ps1",
+	"cmd":             "bat",
+	"dos":             "bat",
+	"py":              "py",
+	"python":          "py",
+	"ruby":            "rb",
+	"rb":              "rb",
+}
+
+func inferFileExtension(languageID string) string {
+	return fileExtensionByLanguageID[languageID]
+}
diff --git a/internal/command/command_file_test.go b/internal/command/command_file_test.go
index a63d2100..f051b9a2 100644
--- a/internal/command/command_file_test.go
+++ b/internal/command/command_file_test.go
@@ -40,4 +40,23 @@ func TestFileCommand(t *testing.T) {
 
 		testExecuteCommand(t, cfg, nil, "test\n", "")
 	})
+
+	// TypeScript runner requires the file extension to be .ts.
+	t.Run("TypeScript", func(t *testing.T) {
+		t.Parallel()
+
+		cfg := &ProgramConfig{
+			LanguageId: "ts",
+			Source: &runnerv2alpha1.ProgramConfig_Script{
+				Script: `function print(message: string): void {
+	console.log(message)
+}
+print("important message")
+`,
+			},
+			Mode: runnerv2alpha1.CommandMode_COMMAND_MODE_FILE,
+		}
+
+		testExecuteCommand(t, cfg, nil, "important message\n", "")
+	})
 }