diff --git a/src/library.cpp b/src/library.cpp
index 25d08a858..4f3b58754 100644
--- a/src/library.cpp
+++ b/src/library.cpp
@@ -350,10 +350,11 @@ Xapian::Query buildXapianQueryFromFilterQuery(const Filter& filter)
   //queryParser.set_stemming_strategy(Xapian::QueryParser::STEM_SOME);
   const auto flags = Xapian::QueryParser::FLAG_PHRASE
                    | Xapian::QueryParser::FLAG_BOOLEAN
+                   | Xapian::QueryParser::FLAG_BOOLEAN_ANY_CASE
                    | Xapian::QueryParser::FLAG_LOVEHATE
                    | Xapian::QueryParser::FLAG_WILDCARD
                    | partialQueryFlag;
-  return queryParser.parse_query(filter.getQuery(), flags);
+  return queryParser.parse_query(normalizeText(filter.getQuery()), flags);
 }
 
 Xapian::Query nameQuery(const std::string& name)
diff --git a/test/library.cpp b/test/library.cpp
index e48564b32..209be4a87 100644
--- a/test/library.cpp
+++ b/test/library.cpp
@@ -436,12 +436,31 @@ TEST_F(LibraryTest, filterByQuery)
     "Mythology & Folklore Stack Exchange"
   );
 
+  // filtering by query is diacritics insensitive on titles
+  EXPECT_FILTER_RESULTS(kiwix::Filter().query("mathematiques"),
+    "Mathématiques",
+  );
+  EXPECT_FILTER_RESULTS(kiwix::Filter().query("èxchângé"),
+    "Islam Stack Exchange",
+    "Movies & TV Stack Exchange",
+    "Mythology & Folklore Stack Exchange"
+  );
+
   // filtering by query is case insensitive on description/summary
   EXPECT_FILTER_RESULTS(kiwix::Filter().query("enTHUSiaSTS"),
     "Movies & TV Stack Exchange",
     "Mythology & Folklore Stack Exchange"
   );
 
+  // filtering by query is diacritics insensitive on description/summary
+  EXPECT_FILTER_RESULTS(kiwix::Filter().query("selection"),
+    "Géographie par Wikipédia"
+  );
+  EXPECT_FILTER_RESULTS(kiwix::Filter().query("enthúsïåsts"),
+    "Movies & TV Stack Exchange",
+    "Mythology & Folklore Stack Exchange"
+  );
+
   // by default, filtering by query assumes partial query
   EXPECT_FILTER_RESULTS(kiwix::Filter().query("Wiki"),
     "Encyclopédie de la Tunisie",