diff --git a/docs/ARCHITECTURE.md b/docs/ARCHITECTURE.md
index 7746c9913d..6d2cae8954 100644
--- a/docs/ARCHITECTURE.md
+++ b/docs/ARCHITECTURE.md
@@ -1061,7 +1061,8 @@ sequenceDiagram
 - **Filesystem-only checkpoint**: `memory: false` on snapshot-template creation exports the
   rootfs and no memfile, resumes the same Firecracker process, and produces a template whose
   sandboxes cold-boot; the source keeps running. Routed by its own flag,
-  `filesystem-only-checkpoint`, independent of `in-place-checkpoint` (no memory is exported, so
+  `filesystem-only-checkpoint` (`FILESYSTEM_ONLY_CHECKPOINT` for a deployment without
+  LaunchDarkly), independent of `in-place-checkpoint` (no memory is exported, so
   the sync-WP tracking, the Firecracker release gate and the balloon gate play no part). The
   API refuses it before the sandbox leaves Running when the flag is off for the team (400,
   `snapshot_filesystem_only_disabled`) or when the sandbox's node runs an orchestrator
diff --git a/packages/shared/pkg/featureflags/flags.go b/packages/shared/pkg/featureflags/flags.go
index 7d3106e85b..f43a8b9d2c 100644
--- a/packages/shared/pkg/featureflags/flags.go
+++ b/packages/shared/pkg/featureflags/flags.go
@@ -262,8 +262,10 @@ var (
 	// sync-WP tracking, the Firecracker release and the balloon that gate the
 	// memory in-place path play no part. Off (the default) refuses the
 	// request before anything is touched; there is no memory fallback, since
-	// the caller asked for a template that cold-boots.
-	FilesystemOnlyCheckpointFlag = NewBoolFlag("filesystem-only-checkpoint", false)
+	// the caller asked for a template that cold-boots. The fallback reads
+	// FILESYSTEM_ONLY_CHECKPOINT so a deployment without LaunchDarkly can turn
+	// it on.
+	FilesystemOnlyCheckpointFlag = NewBoolFlag("filesystem-only-checkpoint", envBoolOr("FILESYSTEM_ONLY_CHECKPOINT", false))
 
 	// EnvdInitHeldRequestFlag makes a start whose envd is at or above
 	// utils.MinEnvdVersionForHeldInit wait on one /init for its whole envd-wait budget