diff --git a/include/library.h b/include/library.h
index 856a3a9e..fa8f2426 100644
--- a/include/library.h
+++ b/include/library.h
@@ -106,7 +106,15 @@ class Filter {
     Filter& rejectTags(const Tags& tags);
 
     Filter& category(std::string category);
+
+    /**
+     *  Set the filter to only accept books in the specified language.
+     *
+     *  Multiple languages can be specified as a comma-separated list (in
+     *  which case a book in any of those languages will match).
+     */
     Filter& lang(std::string lang);
+
     Filter& publisher(std::string publisher);
     Filter& creator(std::string creator);
     Filter& maxSize(size_t size);
diff --git a/src/library.cpp b/src/library.cpp
index 508d7c8e..fb9fc035 100644
--- a/src/library.cpp
+++ b/src/library.cpp
@@ -535,9 +535,20 @@ Xapian::Query categoryQuery(const std::string& category)
   return Xapian::Query("XC" + normalizeText(category));
 }
 
-Xapian::Query langQuery(const std::string& lang)
+Xapian::Query langQuery(const std::string& commaSeparatedLanguageList)
 {
-  return Xapian::Query("L" + normalizeText(lang));
+  Xapian::Query q;
+  bool firstIteration = true;
+  for ( const auto& lang : kiwix::split(commaSeparatedLanguageList, ",") ) {
+    const Xapian::Query singleLangQuery("L" + normalizeText(lang));
+    if ( firstIteration ) {
+      q = singleLangQuery;
+      firstIteration = false;
+    } else {
+      q = Xapian::Query(Xapian::Query::OP_OR, q, singleLangQuery);
+    }
+  }
+  return q;
 }
 
 Xapian::Query publisherQuery(const std::string& publisher)
diff --git a/src/server/internalServer.cpp b/src/server/internalServer.cpp
index 378f516f..ceb5dc41 100644
--- a/src/server/internalServer.cpp
+++ b/src/server/internalServer.cpp
@@ -1036,9 +1036,6 @@ InternalServer::search_catalog(const RequestContext& request,
                                kiwix::OPDSDumper& opdsDumper)
 {
     const auto filter = get_search_filter(request);
-    const std::string q = filter.hasQuery()
-                        ? filter.getQuery()
-                        : "<Empty query>";
     std::vector<std::string> bookIdsToDump = mp_library->filter(filter);
     const auto totalResults = bookIdsToDump.size();
     const size_t count = request.get_optional_param("count", 10UL);
diff --git a/test/library_server.cpp b/test/library_server.cpp
index 4afcbc10..f61d9428 100644
--- a/test/library_server.cpp
+++ b/test/library_server.cpp
@@ -114,7 +114,7 @@ std::string maskVariableOPDSFeedData(std::string s)
   "569344" \
 )
 
-#define CHARLES_RAY_CATALOG_ENTRY _CHARLES_RAY_CATALOG_ENTRY("zimfile%26other")
+#define CHARLES_RAY_CATALOG_ENTRY           _CHARLES_RAY_CATALOG_ENTRY("zimfile%26other")
 #define CHARLES_RAY_CATALOG_ENTRY_NO_MAPPER _CHARLES_RAY_CATALOG_ENTRY("charlesray")
 
 #define _RAY_CHARLES_CATALOG_ENTRY(CONTENT_NAME) CATALOG_ENTRY(\
@@ -133,7 +133,7 @@ std::string maskVariableOPDSFeedData(std::string s)
   "569344"\
 )
 
-#define RAY_CHARLES_CATALOG_ENTRY _RAY_CHARLES_CATALOG_ENTRY("zimfile")
+#define RAY_CHARLES_CATALOG_ENTRY           _RAY_CHARLES_CATALOG_ENTRY("zimfile")
 #define RAY_CHARLES_CATALOG_ENTRY_NO_MAPPER _RAY_CHARLES_CATALOG_ENTRY("raycharles")
 
 #define UNCATEGORIZED_RAY_CHARLES_CATALOG_ENTRY CATALOG_ENTRY(\
@@ -317,6 +317,44 @@ TEST_F(LibraryServerTest, catalog_search_by_category)
   );
 }
 
+TEST_F(LibraryServerTest, catalog_search_by_language)
+{
+  {
+    const auto r = zfs1_->GET("/ROOT/catalog/search?lang=eng");
+    EXPECT_EQ(r->status, 200);
+    EXPECT_EQ(maskVariableOPDSFeedData(r->body),
+      OPDS_FEED_TAG
+      "  <id>12345678-90ab-cdef-1234-567890abcdef</id>\n"
+      "  <title>Filtered zims (lang=eng)</title>\n"
+      "  <updated>YYYY-MM-DDThh:mm:ssZ</updated>\n"
+      "  <totalResults>1</totalResults>\n"
+      "  <startIndex>0</startIndex>\n"
+      "  <itemsPerPage>1</itemsPerPage>\n"
+      CATALOG_LINK_TAGS
+      RAY_CHARLES_CATALOG_ENTRY
+      "</feed>\n"
+    );
+  }
+
+  {
+    const auto r = zfs1_->GET("/ROOT/catalog/search?lang=eng,fra");
+    EXPECT_EQ(r->status, 200);
+    EXPECT_EQ(maskVariableOPDSFeedData(r->body),
+      OPDS_FEED_TAG
+      "  <id>12345678-90ab-cdef-1234-567890abcdef</id>\n"
+      "  <title>Filtered zims (lang=eng,fra)</title>\n"
+      "  <updated>YYYY-MM-DDThh:mm:ssZ</updated>\n"
+      "  <totalResults>2</totalResults>\n"
+      "  <startIndex>0</startIndex>\n"
+      "  <itemsPerPage>2</itemsPerPage>\n"
+      CATALOG_LINK_TAGS
+      RAY_CHARLES_CATALOG_ENTRY
+      CHARLES_RAY_CATALOG_ENTRY
+      "</feed>\n"
+    );
+  }
+}
+
 TEST_F(LibraryServerTest, catalog_search_results_pagination)
 {
   {
@@ -667,6 +705,40 @@ TEST_F(LibraryServerTest, catalog_v2_entries_filtered_by_search_terms)
   );
 }
 
+TEST_F(LibraryServerTest, catalog_v2_entries_filtered_by_language)
+{
+  {
+    const auto r = zfs1_->GET("/ROOT/catalog/v2/entries?lang=eng");
+    EXPECT_EQ(r->status, 200);
+    EXPECT_EQ(maskVariableOPDSFeedData(r->body),
+      CATALOG_V2_ENTRIES_PREAMBLE("?lang=eng")
+      "  <title>Filtered Entries (lang=eng)</title>\n"
+      "  <updated>YYYY-MM-DDThh:mm:ssZ</updated>\n"
+      "  <totalResults>1</totalResults>\n"
+      "  <startIndex>0</startIndex>\n"
+      "  <itemsPerPage>1</itemsPerPage>\n"
+      RAY_CHARLES_CATALOG_ENTRY
+      "</feed>\n"
+    );
+  }
+
+  {
+    const auto r = zfs1_->GET("/ROOT/catalog/v2/entries?lang=eng,fra");
+    EXPECT_EQ(r->status, 200);
+    EXPECT_EQ(maskVariableOPDSFeedData(r->body),
+      CATALOG_V2_ENTRIES_PREAMBLE("?lang=eng,fra")
+      "  <title>Filtered Entries (lang=eng,fra)</title>\n"
+      "  <updated>YYYY-MM-DDThh:mm:ssZ</updated>\n"
+      "  <totalResults>2</totalResults>\n"
+      "  <startIndex>0</startIndex>\n"
+      "  <itemsPerPage>2</itemsPerPage>\n"
+      RAY_CHARLES_CATALOG_ENTRY
+      CHARLES_RAY_CATALOG_ENTRY
+      "</feed>\n"
+    );
+  }
+}
+
 TEST_F(LibraryServerTest, catalog_v2_individual_entry_access)
 {
   const auto r = zfs1_->GET("/ROOT/catalog/v2/entry/raycharles");