diff --git a/plugins/preview-tui b/plugins/preview-tui
index c634cf00..0f5d60ed 100755
--- a/plugins/preview-tui
+++ b/plugins/preview-tui
@@ -86,6 +86,7 @@ NNN_PREVIEWDIR="${NNN_PREVIEWDIR:-$TMPDIR/nnn/previews}"
 NNN_PREVIEWWIDTH="${NNN_PREVIEWWIDTH:-1920}"
 NNN_PREVIEWHEIGHT="${NNN_PREVIEWHEIGHT:-1080}"
 NNN_PARENT="${NNN_FIFO#*.}"
+[ "$NNN_PARENT" -eq "$NNN_PARENT" ] 2>/dev/null || NNN_PARENT=""
 FIFOPID="$TMPDIR/nnn-preview-tui-fifopid.$NNN_PARENT"
 PREVIEWPID="$TMPDIR/nnn-preview-tui-pagerpid.$NNN_PARENT"
 CURSEL="$TMPDIR/nnn-preview-tui-selection.$NNN_PARENT"