diff --git a/box-drawing.c b/box-drawing.c
index f462540e..96de8775 100644
--- a/box-drawing.c
+++ b/box-drawing.c
@@ -15,6 +15,8 @@
 #define LIGHT 1.0
 #define HEAVY 2.0
 
+#pragma GCC optimize("Os")
+
 static int
 thickness(float pts, int dpi)
 {