diff --git a/matrix.go b/matrix.go
index 6e89776..85ba0b8 100644
--- a/matrix.go
+++ b/matrix.go
@@ -60,7 +60,7 @@ var DefaultConfig = HardwareConfig{
 }
 
 type RunTimeConfig struct {
-	gpio_slowdown int
+	Gpio_slowdown int
 }
 
 // HardwareConfig rgb-led-matrix configuration