diff --git a/platform/smallstep-agent.mdx b/platform/smallstep-agent.mdx
index a76b3e78..b9649963 100644
--- a/platform/smallstep-agent.mdx
+++ b/platform/smallstep-agent.mdx
@@ -19,6 +19,7 @@ In this document, we will install, configure, and start the Smallstep Agent on a
     - Ubuntu (Current Stable and LTS)
     - Debian (Current Releases)
     - Fedora (Current Releases)
+- A TPM 2.0 module is required. Smallstep depends on TPMs to create a high-assurance device inventory.
 - We support `amd64` and `arm64` architectures
  The following directories are used by default:
     - runtime state in `/run/step-agent`