diff --git a/buildpack.md b/buildpack.md
index 41badd3..3f79524 100644
--- a/buildpack.md
+++ b/buildpack.md
@@ -500,7 +500,7 @@ The purpose of the generation phase is to generate Dockerfiles that can be used
 
 ### Process
 
-See the [Image Extension Specification](#image-extension.md).
+See the [Image Extension Specification](#image_extension.md).
 
 ## Phase #4: Extension (image extensions only)