diff --git a/cmd/verstak-gui/bindings_debug.go b/cmd/verstak-gui/bindings_debug.go
index f462935..f684774 100644
--- a/cmd/verstak-gui/bindings_debug.go
+++ b/cmd/verstak-gui/bindings_debug.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"log"
 	"os"
 	"path/filepath"
 	"time"
@@ -13,6 +14,7 @@ func (a *App) WriteDebugLog(msg string) {
 	if !a.IsReady() {
 		return
 	}
+	log.Printf("[js] %s", msg)
 	logPath := filepath.Join(a.vault, ".verstak", "debug.log")
 	line := fmt.Sprintf("[%s] %s\n", time.Now().Format("2006-01-02T15:04:05"), msg)
 	f, err := os.OpenFile(logPath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0o644)
diff --git a/contrib/plugins/calendar/panels/calendar.html b/contrib/plugins/calendar/panels/calendar.html
index 4eed23c..d3f3c3e 100644
--- a/contrib/plugins/calendar/panels/calendar.html
+++ b/contrib/plugins/calendar/panels/calendar.html
@@ -431,6 +431,7 @@ body {
 
     switch (msg.type) {
       case 'calendar-data':
+        try { window.parent.go.main.App.WriteDebugLog('[iframe] received calendar-data, events=' + (msg.events ? msg.events.length : 0) + ', categories=' + (msg.categories ? msg.categories.length : 0)); } catch(e) { try { console.log('iframe debug error: ' + e); } catch(e2) {} }
         if (msg.events) state.events = msg.events;
         if (msg.categories) state.categories = msg.categories;
         state.eventsLoaded = true;