diff --git a/docs/api-guide/testing.md b/docs/api-guide/testing.md
index 261df80f2..b3c4edad8 100644
--- a/docs/api-guide/testing.md
+++ b/docs/api-guide/testing.md
@@ -5,7 +5,7 @@ source:
 
 # Testing
 
-> Code without tests is broken as designed.
+> Code without tests is broken by design.
 >
 > — [Jacob Kaplan-Moss][cite]