fix typo
diff --git a/ReleaseInstructions b/ReleaseInstructions
index c16245e..2739726 100644
--- a/ReleaseInstructions
+++ b/ReleaseInstructions
@@ -308,7 +308,7 @@
     * ivy.xml in release subdirectory
     * WHATSNEW (add a new section)
     * src/etc/testcases/taskdefs/conditions/antversion.xml
-    * snap/snapcraft.yml (bump version to [newversion]alpha and set grade
+    * snap/snapcraft.yaml (bump version to [newversion]alpha and set grade
       to devel)
 
     Amend the merge commit