diff --git a/renderer/image.go b/renderer/image.go
index 689b6dc..f273df9 100644
--- a/renderer/image.go
+++ b/renderer/image.go
@@ -2,6 +2,7 @@ package renderer
 
 import (
 	"bytes"
+	"fmt"
 	"path/filepath"
 	"strconv"
 	"strings"
@@ -143,6 +144,9 @@ func (r *ConfluenceImageRenderer) renderImage(writer util.BufWriter, source []by
 			},
 		)
 	} else {
+		if len(attachments) == 0 {
+			return ast.WalkStop, fmt.Errorf("no attachment resolved for %q", string(n.Destination))
+		}
 
 		r.Attachments.Attach(attachments[0])
 
diff --git a/renderer/mkDocsAdmonition.go b/renderer/mkDocsAdmonition.go
index 7f6e72a..20244d8 100644
--- a/renderer/mkDocsAdmonition.go
+++ b/renderer/mkDocsAdmonition.go
@@ -2,6 +2,7 @@ package renderer
 
 import (
 	"fmt"
+	stdhtml "html"
 	"strconv"
 
 	parser "github.com/stefanfritsch/goldmark-admonitions"
@@ -81,7 +82,7 @@ func (r *ConfluenceMkDocsAdmonitionRenderer) renderMkDocsAdmonition(writer util.
 
 		title, _ := strconv.Unquote(string(n.Title))
 		if title != "" {
-			titleHTML := fmt.Sprintf("<p><strong>%s</strong></p>\n", title)
+			titleHTML := fmt.Sprintf("<p><strong>%s</strong></p>\n", stdhtml.EscapeString(title))
 			if _, err := writer.Write([]byte(titleHTML)); err != nil {
 				return ast.WalkStop, err
 			}