diff --git a/concepts/sandboxes.mdx b/concepts/sandboxes.mdx
index 64bf8ef..ba34567 100644
--- a/concepts/sandboxes.mdx
+++ b/concepts/sandboxes.mdx
@@ -256,6 +256,10 @@ Sandboxes don't take `instance_size`, `ami` or `storage`. See [SandboxStepInfras
 
 ### Automatic sizing
 
+<Note>
+  Automatic sizing is in preview. [Contact support](/contact-support) to share feedback.
+</Note>
+
 Set `cpu`, `memory` or `disk` to `auto` and Ravion sizes the sandbox from the step's earlier runs. `auto` needs `interruptible: true` on the same step; a step without it must set fixed values, and the pipeline won't save otherwise.
 
 - The first run gets 4 vCPU, 16 GiB of memory and 40 GiB of disk.
diff --git a/github-actions/runners.mdx b/github-actions/runners.mdx
index e0c24fd..15b3692 100644
--- a/github-actions/runners.mdx
+++ b/github-actions/runners.mdx
@@ -138,6 +138,10 @@ Mark jobs that are safe to run twice as `interruptible=true`, such as tests, lin
 
 ### Automatic sizing
 
+<Note>
+  Automatic sizing is in preview. [Contact support](/contact-support) to share feedback.
+</Note>
+
 Stop guessing machine sizes. Set `cpu`, `memory` or `disk` to `auto` and Ravion sizes the sandbox for you.
 
 ```yaml