diff --git a/src/report/report-system/report-utilities.scm b/src/report/report-system/report-utilities.scm
index 0274b3392e..1d5b86cba0 100644
--- a/src/report/report-system/report-utilities.scm
+++ b/src/report/report-system/report-utilities.scm
@@ -700,6 +700,8 @@
 			    0))
 
 (define (gnc:report-percent-done percent)
+  (if (> percent 100)
+      (gnc:warn "report more than 100% finished. " percent))
   (gnc-window-show-progress "" percent))
 
 (define (gnc:report-finished)