diff --git a/tools/export-seg-model.sh b/tools/export-seg-model.sh
index 911effa..261fad5 100755
--- a/tools/export-seg-model.sh
+++ b/tools/export-seg-model.sh
@@ -28,7 +28,12 @@ OUT="${REPO}/models/segment"
 
 MODEL="${1:-yolo26n-seg}"
 IMGSZ="${2:-640}"
-WORK="$(mktemp -d)"
+# Not `mktemp -d`: the default TMPDIR is `/tmp`, which on most current Linux
+# distributions is a tmpfs — RAM, sized at half of physical memory. The venv
+# below pulls torch, several gigabytes of it, and installing that into RAM
+# either evicts the user's page cache or fails outright with ENOSPC on a
+# machine that has hundreds of gigabytes of actual disk free.
+WORK="$(mktemp -d -p "${TMPDIR:-/var/tmp}")"
 trap 'rm -rf "${WORK}"' EXIT
 
 echo "==> exporting ${MODEL} at imgsz=${IMGSZ} in ${WORK}"