diff --git a/main.c b/main.c
index 99d3438..85d6a1d 100644
--- a/main.c
+++ b/main.c
@@ -83,10 +83,10 @@ int drm_open_device(char* fileName)
 int main(int argc, char** argv)
 {
 	if(argc < 2) {
-		printf("Usage: %s [DEVICE]\n", argv[0]);
+		printf("Usage: %s [DEVICE]\n[DEVICE] is sysfs path to a drm device like /dev/dri/card0", argv[0]);
 		return 1;
 	}
-	int device = drm_open_device("/dev/dri/card2");
+	int device = drm_open_device(argv[1]);
 	if(device < 0)
 		return 2;