diff --git a/README.md b/README.md
index ca8abf3..c3245ba 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,8 @@
 # 4JLibs-VS2012
 
+## WARNING
+This needs the [Windows 10 SDK](https://learn.microsoft.com/en-us/windows/apps/windows-sdk/downloads#windows-10) to build `4J_Render`.
+
 ## Implementation
 
 For implementation details, please look at the [IMPLEMENTATION_GUIDE.md](.gitea/IMPLEMENTATION_GUIDE.md) file