diff --git a/gosrc/main.go b/gosrc/main.go
index b80f21d..8815f27 100644
--- a/gosrc/main.go
+++ b/gosrc/main.go
@@ -43,9 +43,9 @@ func handleEbook(c *fiber.Ctx) error {
 
 	cmd := exec.Command(path.Join(rootPath, "genpdf"), "generate:ebook", sp)
 
-	o, err := cmd.Output()
+	o, err := cmd.CombinedOutput()
 	if err != nil {
-		return c.Status(fiber.StatusInternalServerError).SendString(fmt.Sprintf("failed to convert ebook: %s", err))
+		return c.Status(fiber.StatusInternalServerError).SendString(fmt.Sprintf("failed to convert ebook: %s", string(o)))
 	}
 	err = c.Download(strings.TrimSpace(string(o)))
 	if err != nil {