diff --git a/README.md b/README.md
index 56452b98..9204b43b 100644
--- a/README.md
+++ b/README.md
@@ -37,6 +37,8 @@ in your favourite language.*
 
 ## 2018
 
+**WARNING:** All of these likely contain spoilers.
+
 ### Solutions
 
 #### C#