diff --git a/backend/webdav/api/types.go b/backend/webdav/api/types.go
index eab79dccf..8fe89279d 100644
--- a/backend/webdav/api/types.go
+++ b/backend/webdav/api/types.go
@@ -69,7 +69,7 @@ type Prop struct {
 	Status       []string  `xml:"DAV: status"`
 	Name         string    `xml:"DAV: prop>displayname,omitempty"`
 	Type         *xml.Name `xml:"DAV: prop>resourcetype>collection,omitempty"`
-	IsCollection *int      `xml:"DAV: prop>iscollection,omitempty"` // this is a Microsoft extension see #2716
+	IsCollection *string   `xml:"DAV: prop>iscollection,omitempty"` // this is a Microsoft extension see #2716
 	Size         int64     `xml:"DAV: prop>getcontentlength,omitempty"`
 	Modified     Time      `xml:"DAV: prop>getlastmodified,omitempty"`
 	Checksums    []string  `xml:"prop>checksums>checksum,omitempty"`
diff --git a/backend/webdav/webdav.go b/backend/webdav/webdav.go
index 54e11f505..889da8cdf 100644
--- a/backend/webdav/webdav.go
+++ b/backend/webdav/webdav.go
@@ -173,9 +173,16 @@ func itemIsDir(item *api.Response) bool {
 		fs.Debugf(nil, "Unknown resource type %q/%q on %q", t.Space, t.Local, item.Props.Name)
 	}
 	// the iscollection prop is a Microsoft extension, but if present it is a reliable indicator
-	// if the above check failed - see #2716
+	// if the above check failed - see #2716. This can be an integer or a boolean - see #2964
 	if t := item.Props.IsCollection; t != nil {
-		return *t != 0
+		switch x := strings.ToLower(*t); x {
+		case "0", "false":
+			return false
+		case "1", "true":
+			return true
+		default:
+			fs.Debugf(nil, "Unknown value %q for IsCollection", x)
+		}
 	}
 	return false
 }