diff --git a/cmd/tank/config.go b/cmd/tank/config.go
index 95562ddda4f32a3eafbfc3cb75c8b80cc911cb2c..f017fae1b8533494e116f2ebc2994f90e95b3037 100644
--- a/cmd/tank/config.go
+++ b/cmd/tank/config.go
@@ -42,7 +42,8 @@ type CorsConfig struct {
 }
 
 func (c *CorsConfig) ExpandEnv() {
-	if _, exists := os.LookupEnv("CORS_ALLOW_CREDENTIALS"); exists {
+	allowCredentials := strings.ToLower(os.Getenv("CORS_ALLOW_CREDENTIALS"))
+	if allowCredentials == "1" || allowCredentials == "true" || allowCredentials == "on" || allowCredentials == "yes" {
 		c.AllowCredentials = true
 	}
 
@@ -50,7 +51,8 @@ func (c *CorsConfig) ExpandEnv() {
 		c.AllowedOrigins = strings.Split(allowedOrigins, ",")
 	}
 
-	if _, exists := os.LookupEnv("CORS_DEBUG"); exists {
+	debug := strings.ToLower(os.Getenv("CORS_DEBUG"))
+	if debug == "1" || debug == "true" || debug == "on" || debug == "yes" {
 		c.Debug = true
 	}
 }