diff --git a/core.go b/core.go
index cb31680..967eaca 100644
--- a/core.go
+++ b/core.go
@@ -105,7 +105,7 @@ func (app *App) Run(router *httprouter.Router) {
 	// check if template engine is enable
 	TemplateEnableStr := os.Getenv("TEMPLATE_ENABLE")
 	if "" == TemplateEnableStr {
-		TemplateEnableStr = 'false'
+		TemplateEnableStr = "false"
 	}
 	TemplateEnable, _ := strconv.ParseBool(TemplateEnableStr)
 	// if enabled,