diff --git a/slides/presenting-accessibly.html b/slides/presenting-accessibly.html
index c3399b622924217482404c162ee6afd54448b4ff..42cdd472831b5106570bc2d68774391b23187913 100644
--- a/slides/presenting-accessibly.html
+++ b/slides/presenting-accessibly.html
@@ -154,7 +154,7 @@ Can a BVI person follow your presentation and get the same information as someon
 - Image descriptions
 - Use headers & styles
 - Color contrast
-  - We'll talk about this more, but you can use [this tool](TBD) to make sure that people with color blindness or other color-related accessibility needs can read your slides
+  - We'll talk about this more, but you can use [this tool](https://webaim.org/resources/contrastchecker/) to make sure that people with color blindness or other color-related accessibility needs can read your slides
 
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 # Slideshow Basics (4/9)