diff --git a/core/src/statusbar.sld b/core/src/statusbar.sld
index e3fb628..7d42eb5 100644
--- a/core/src/statusbar.sld
+++ b/core/src/statusbar.sld
@@ -87,9 +87,9 @@
       (define (draw-status-bar)
         (fprintf err-port "\r\x1B[2K") ; ]
         (if (<= (string-length status-bar) terminal-width)
-          (write-string status-bar err-port)
+          (fprintf err-port "~A" status-bar)
           (begin
-            (write-string status-bar err-port 0 (- terminal-width 3))
+            (fprintf err-port "~A" (string-copy status-bar 0 (- terminal-width 3)))
             (write-string "..." err-port)))
         (flush-output-port err-port)
         (set! need-redraw #f))
@@ -202,7 +202,11 @@
          ((and (eqv? event 'activity-start) (eq? (nix-activity-type data) 105))
           (set! build-activity-mapping
             (mapping-set! build-activity-mapping (nix-activity-id data)
-              (string-drop (string-drop-while (vector-ref (nix-activity-fields data) 0) (lambda (f) (not (char=? f #\-)))) 1))))
+              (string-drop (string-drop-while (vector-ref (nix-activity-fields data) 0) (lambda (f) (not (char=? f #\-)))) 1)))
+          (mutex-lock! out-mutex)
+          (set! statusbar-msg (string-append "building " (vector-ref (nix-activity-fields data) 0)))
+          (mutex-unlock! out-mutex)
+          (rerender-status-bar))
          ((eqv? event 'activity-start) (when (> (string-length (nix-activity-string data)) 0) (set! statusbar-msg (nix-activity-string data)) (rerender-status-bar)))
          ((eqv? event 'activity-stop)
           (set! build-activity-mapping (mapping-delete! build-activity-mapping data)))