diff --git a/include/name_mapper.h b/include/name_mapper.h
index 4247c5c3..8b8bde62 100644
--- a/include/name_mapper.h
+++ b/include/name_mapper.h
@@ -54,6 +54,7 @@ class HumanReadableNameMapper : public NameMapper {
     virtual ~HumanReadableNameMapper() = default;
     virtual std::string getNameForId(const std::string& id) const;
     virtual std::string getIdForName(const std::string& name) const;
+    static std::string removeDateFromBookId(const std::string& bookId);
 };
 
 class UpdatableNameMapper : public NameMapper {
diff --git a/src/library.cpp b/src/library.cpp
index 1bc36090..7b0db077 100644
--- a/src/library.cpp
+++ b/src/library.cpp
@@ -28,6 +28,7 @@
 #include "tools/stringTools.h"
 #include "tools/otherTools.h"
 #include "tools/concurrent_cache.h"
+#include "name_mapper.h"
 
 #include <pugixml.hpp>
 #include <algorithm>
@@ -462,7 +463,7 @@ void Library::updateBookDB(const Book& book)
   indexer.index_text(normalizeText(book.getName()),      1, "XN");
   indexer.index_text(normalizeText(book.getCategory()),  1, "XC");
   const auto bookName = book.getHumanReadableIdFromPath();
-  const auto aliasName = replaceRegex(bookName, "", "_[[:digit:]]{4}-[[:digit:]]{2}$");
+  const auto aliasName = HumanReadableNameMapper::removeDateFromBookId(bookName);
   indexer.index_text(normalizeText(aliasName), 1, "XF");
 
   for ( const auto& tag : split(normalizeText(book.getTags()), ";") ) {
diff --git a/src/name_mapper.cpp b/src/name_mapper.cpp
index dccf40c9..6877e229 100644
--- a/src/name_mapper.cpp
+++ b/src/name_mapper.cpp
@@ -34,7 +34,7 @@ HumanReadableNameMapper::HumanReadableNameMapper(kiwix::Library& library, bool w
     if (!withAlias)
       continue;
 
-    auto aliasName = replaceRegex(bookName, "", "_[[:digit:]]{4}-[[:digit:]]{2}$");
+    auto aliasName = removeDateFromBookId(bookName);
     if (aliasName == bookName) {
       continue;
     }
@@ -51,6 +51,10 @@ HumanReadableNameMapper::HumanReadableNameMapper(kiwix::Library& library, bool w
   }
 }
 
+std::string HumanReadableNameMapper::removeDateFromBookId(const std::string& bookId) {
+  return replaceRegex(bookId, "", "_[[:digit:]]{4}-[[:digit:]]{2}$");
+}
+
 std::string HumanReadableNameMapper::getNameForId(const std::string& id) const {
   return m_idToName.at(id);
 }