diff --git a/rockcraft/extensions/extension.py b/rockcraft/extensions/extension.py
index efe87b63a..2955c6b3a 100644
--- a/rockcraft/extensions/extension.py
+++ b/rockcraft/extensions/extension.py
@@ -88,7 +88,9 @@ def validate(self, extension_name: str) -> None:
         ):
             raise errors.ExtensionError(
                 f"Extension is experimental: {extension_name!r}",
-                docs_url="https://rockcraft.io/docs/supported-extensions",
+                doc_slug="/reference/extensions/",
+                resolution="Run with ROCKCRAFT_ENABLE_EXPERIMENTAL_EXTENSIONS=True to enable "
+                "experimental extensions.",
             )
 
         if self.is_experimental(base):