diff --git a/scripts/guix-data-service.in b/scripts/guix-data-service.in
index 172838f..2244c0e 100644
--- a/scripts/guix-data-service.in
+++ b/scripts/guix-data-service.in
@@ -137,6 +137,9 @@
 (setvbuf (current-output-port) 'line)
 (setvbuf (current-error-port) 'line)
 
+(unless (getenv "COLUMNS")
+  (setenv "COLUMNS" "128"))
+
 (let ((opts (parse-options (cdr (program-arguments)))))
   (when (assq-ref opts 'repl)
     ((@@ (ice-9 top-repl) call-with-sigint)