diff --git a/src/zip.cpp b/src/zip.cpp
index 4020145..8cc1d57 100644
--- a/src/zip.cpp
+++ b/src/zip.cpp
@@ -181,6 +181,7 @@ std::vector<std::string> list_spine(const fs::path &filepath)
                     .attribute("full-path")
                     .value();
             }
+            cerr << translate("ERROR: ") << result.description() << '\n';
 
             return "";
         }()};
@@ -219,6 +220,11 @@ std::vector<std::string> list_spine(const fs::path &filepath)
                 spine_filepaths.emplace_back(href);
             }
         }
+        else
+        {
+            cerr << translate("ERROR: ") << "XML: " << result.description()
+                 << '\n';
+        }
     }
 
     if (opf_file_path.empty() || spine_filepaths.empty())