diff --git a/src/calls.rs b/src/calls.rs
index c3861e5efe..da5ad0a1bc 100644
--- a/src/calls.rs
+++ b/src/calls.rs
@@ -10,11 +10,11 @@ use crate::context::{Context, WeakContext};
 use crate::events::EventType;
 use crate::headerdef::HeaderDef;
 use crate::log::warn;
-use crate::message::{self, Message, MsgId, Viewtype};
+use crate::message::{Message, MsgId, Viewtype};
 use crate::mimeparser::{MimeMessage, SystemMessage};
 use crate::net::dns::lookup_host_with_cache;
 use crate::param::Param;
-use crate::tools::time;
+use crate::tools::{normalize_text, time};
 use anyhow::{Context as _, Result, ensure};
 use sdp::SessionDescription;
 use serde::Serialize;
@@ -86,7 +86,7 @@ impl CallInfo {
             .sql
             .execute(
                 "UPDATE msgs SET txt=?, txt_normalized=? WHERE id=?",
-                (text, message::normalize_text(text), self.msg.id),
+                (text, normalize_text(text), self.msg.id),
             )
             .await?;
         Ok(())
diff --git a/src/chat.rs b/src/chat.rs
index dc8a9530a0..b8d6c8c520 100644
--- a/src/chat.rs
+++ b/src/chat.rs
@@ -45,7 +45,7 @@ use crate::sync::{self, Sync::*, SyncData};
 use crate::tools::{
     IsNoneOrEmpty, SystemTime, buf_compress, create_broadcast_secret, create_id,
     create_outgoing_rfc724_mid, create_smeared_timestamp, create_smeared_timestamps, get_abs_path,
-    gm2local_offset, smeared_time, time, truncate_msg_text,
+    gm2local_offset, normalize_text, smeared_time, time, truncate_msg_text,
 };
 use crate::webxdc::StatusUpdateSerial;
 use crate::{chatlist_events, imap};
@@ -286,10 +286,11 @@ impl ChatId {
         let timestamp = cmp::min(timestamp, smeared_time(context));
         let row_id =
             context.sql.insert(
-                "INSERT INTO chats (type, name, grpid, blocked, created_timestamp, protected, param) VALUES(?, ?, ?, ?, ?, 0, ?);",
+                "INSERT INTO chats (type, name, name_normalized, grpid, blocked, created_timestamp, protected, param) VALUES(?, ?, ?, ?, ?, ?, 0, ?)",
                 (
                     chattype,
                     &grpname,
+                    normalize_text(&grpname),
                     grpid,
                     create_blocked,
                     timestamp,
@@ -782,7 +783,7 @@ impl ChatId {
                                     time(),
                                     msg.viewtype,
                                     &msg.text,
-                                    message::normalize_text(&msg.text),
+                                    normalize_text(&msg.text),
                                     msg.param.to_string(),
                                     msg.in_reply_to.as_deref().unwrap_or_default(),
                                     msg.id,
@@ -823,7 +824,7 @@ impl ChatId {
                         msg.viewtype,
                         MessageState::OutDraft,
                         &msg.text,
-                        message::normalize_text(&msg.text),
+                        normalize_text(&msg.text),
                         msg.param.to_string(),
                         1,
                         msg.in_reply_to.as_deref().unwrap_or_default(),
@@ -1919,7 +1920,7 @@ impl Chat {
                         msg.viewtype,
                         msg.state,
                         msg_text,
-                        message::normalize_text(&msg_text),
+                        normalize_text(&msg_text),
                         &msg.subject,
                         msg.param.to_string(),
                         msg.hidden,
@@ -1970,7 +1971,7 @@ impl Chat {
                         msg.viewtype,
                         msg.state,
                         msg_text,
-                        message::normalize_text(&msg_text),
+                        normalize_text(&msg_text),
                         &msg.subject,
                         msg.param.to_string(),
                         msg.hidden,
@@ -2274,8 +2275,8 @@ async fn update_special_chat_name(
         context
             .sql
             .execute(
-                "UPDATE chats SET name=? WHERE id=? AND name!=?",
-                (&name, chat_id, &name),
+                "UPDATE chats SET name=?, name_normalized=? WHERE id=? AND name!=?",
+                (&name, normalize_text(&name), chat_id, &name),
             )
             .await?;
     }
@@ -2388,11 +2389,12 @@ impl ChatIdBlocked {
             .transaction(move |transaction| {
                 transaction.execute(
                     "INSERT INTO chats
-                     (type, name, param, blocked, created_timestamp)
-                     VALUES(?, ?, ?, ?, ?)",
+                     (type, name, name_normalized, param, blocked, created_timestamp)
+                     VALUES(?, ?, ?, ?, ?, ?)",
                     (
                         Chattype::Single,
-                        chat_name,
+                        &chat_name,
+                        normalize_text(&chat_name),
                         params.to_string(),
                         create_blocked as u8,
                         smeared_time,
@@ -2944,7 +2946,7 @@ pub(crate) async fn save_text_edit_to_db(
             "UPDATE msgs SET txt=?, txt_normalized=?, param=? WHERE id=?",
             (
                 new_text,
-                message::normalize_text(new_text),
+                normalize_text(new_text),
                 original_msg.param.to_string(),
                 original_msg.id,
             ),
@@ -3433,9 +3435,15 @@ pub(crate) async fn create_group_ex(
         .sql
         .insert(
             "INSERT INTO chats
-        (type, name, grpid, param, created_timestamp)
-        VALUES(?, ?, ?, \'U=1\', ?);",
-            (Chattype::Group, &chat_name, &grpid, timestamp),
+        (type, name, name_normalized, grpid, param, created_timestamp)
+        VALUES(?, ?, ?, ?, \'U=1\', ?)",
+            (
+                Chattype::Group,
+                &chat_name,
+                normalize_text(&chat_name),
+                &grpid,
+                timestamp,
+            ),
         )
         .await?;
 
@@ -3519,9 +3527,15 @@ pub(crate) async fn create_out_broadcast_ex(
 
         t.execute(
             "INSERT INTO chats
-            (type, name, grpid, created_timestamp)
-            VALUES(?, ?, ?, ?);",
-            (Chattype::OutBroadcast, &chat_name, &grpid, timestamp),
+            (type, name, name_normalized, grpid, created_timestamp)
+            VALUES(?, ?, ?, ?, ?)",
+            (
+                Chattype::OutBroadcast,
+                &chat_name,
+                normalize_text(&chat_name),
+                &grpid,
+                timestamp,
+            ),
         )?;
         let chat_id = ChatId::new(t.last_insert_rowid().try_into()?);
 
@@ -4094,8 +4108,8 @@ async fn rename_ex(
             context
                 .sql
                 .execute(
-                    "UPDATE chats SET name=? WHERE id=?;",
-                    (new_name.to_string(), chat_id),
+                    "UPDATE chats SET name=?, name_normalized=? WHERE id=?",
+                    (&new_name, normalize_text(&new_name), chat_id),
                 )
                 .await?;
             if chat.is_promoted()
@@ -4529,7 +4543,7 @@ pub async fn add_device_msg_with_importance(
                     msg.viewtype,
                     state,
                     &msg.text,
-                    message::normalize_text(&msg.text),
+                    normalize_text(&msg.text),
                     msg.param.to_string(),
                     rfc724_mid,
                 ),
@@ -4668,7 +4682,7 @@ pub(crate) async fn add_info_msg_with_cmd(
             Viewtype::Text,
             MessageState::InNoticed,
             text,
-            message::normalize_text(text),
+            normalize_text(text),
             rfc724_mid,
             ephemeral_timer,
             param.to_string(),
@@ -4710,7 +4724,7 @@ pub(crate) async fn update_msg_text_and_timestamp(
         .sql
         .execute(
             "UPDATE msgs SET txt=?, txt_normalized=?, timestamp=? WHERE id=?;",
-            (text, message::normalize_text(text), timestamp, msg_id),
+            (text, normalize_text(text), timestamp, msg_id),
         )
         .await?;
     context.emit_msgs_changed(chat_id, msg_id);
diff --git a/src/chatlist.rs b/src/chatlist.rs
index 7146b4a586..67ddb9da3d 100644
--- a/src/chatlist.rs
+++ b/src/chatlist.rs
@@ -185,7 +185,7 @@ impl Chatlist {
                 warn!(context, "Cannot update special chat names: {err:#}.")
             }
 
-            let str_like_cmd = format!("%{query}%");
+            let str_like_cmd = format!("%{}%", query.to_lowercase());
             context
                 .sql
                 .query_map_vec(
@@ -201,7 +201,7 @@ impl Chatlist {
                                   ORDER BY timestamp DESC, id DESC LIMIT 1)
                  WHERE c.id>9 AND c.id!=?2
                    AND c.blocked!=1
-                   AND c.name LIKE ?3
+                   AND IFNULL(c.name_normalized,c.name) LIKE ?3
                    AND (NOT ?4 OR EXISTS (SELECT 1 FROM msgs m WHERE m.chat_id = c.id AND m.state == ?5 AND hidden=0))
                  GROUP BY c.id
                  ORDER BY IFNULL(m.timestamp,c.created_timestamp) DESC, m.id DESC;",
@@ -472,7 +472,7 @@ mod tests {
     use crate::chat::save_msgs;
     use crate::chat::{
         add_contact_to_chat, create_group, get_chat_contacts, remove_contact_from_chat,
-        send_text_msg,
+        send_text_msg, set_chat_name,
     };
     use crate::receive_imf::receive_imf;
     use crate::stock_str::StockMessage;
@@ -482,7 +482,7 @@ mod tests {
     use std::time::Duration;
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-    async fn test_try_load() {
+    async fn test_try_load() -> Result<()> {
         let mut tcm = TestContextManager::new();
         let bob = &tcm.bob().await;
         let chat_id1 = create_group(bob, "a chat").await.unwrap();
@@ -552,6 +552,15 @@ mod tests {
             .await
             .unwrap();
         assert_eq!(chats.len(), 1);
+
+        let chat_id = create_group(bob, "Δ-chat").await.unwrap();
+        let chats = Chatlist::try_load(bob, 0, Some("δ"), None).await?;
+        assert_eq!(chats.len(), 1);
+        assert_eq!(chats.ids[0].0, chat_id);
+        set_chat_name(bob, chat_id, "abcδe").await?;
+        let chats = Chatlist::try_load(bob, 0, Some("Δ"), None).await?;
+        assert_eq!(chats.len(), 1);
+        Ok(())
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
diff --git a/src/contact.rs b/src/contact.rs
index 478ad8abfc..7d7e1ca14e 100644
--- a/src/contact.rs
+++ b/src/contact.rs
@@ -36,7 +36,7 @@ use crate::message::MessageState;
 use crate::mimeparser::AvatarAction;
 use crate::param::{Param, Params};
 use crate::sync::{self, Sync::*};
-use crate::tools::{SystemTime, duration_to_str, get_abs_path, time, to_lowercase};
+use crate::tools::{SystemTime, duration_to_str, get_abs_path, normalize_text, time, to_lowercase};
 use crate::{chat, chatlist_events, ensure_and_debug_assert_ne, stock_str};
 
 /// Time during which a contact is considered as seen recently.
@@ -115,9 +115,23 @@ impl ContactId {
         let row = context
             .sql
             .transaction(|transaction| {
+                let authname;
+                let name_or_authname = if !name.is_empty() {
+                    name
+                } else {
+                    authname = transaction.query_row(
+                        "SELECT authname FROM contacts WHERE id=?",
+                        (self,),
+                        |row| {
+                            let authname: String = row.get(0)?;
+                            Ok(authname)
+                        },
+                    )?;
+                    &authname
+                };
                 let is_changed = transaction.execute(
-                    "UPDATE contacts SET name=?1 WHERE id=?2 AND name!=?1",
-                    (name, self),
+                    "UPDATE contacts SET name=?1, name_normalized=?2 WHERE id=?3 AND name!=?1",
+                    (name, normalize_text(name_or_authname), self),
                 )? > 0;
                 if is_changed {
                     update_chat_names(context, transaction, self)?;
@@ -967,11 +981,22 @@ impl Contact {
                         } else {
                             row_name
                         };
+                        let new_authname = if update_authname {
+                            name.to_string()
+                        } else {
+                            row_authname
+                        };
 
                         transaction.execute(
-                            "UPDATE contacts SET name=?, addr=?, origin=?, authname=? WHERE id=?;",
+                            "UPDATE contacts SET name=?, name_normalized=?, addr=?, origin=?, authname=? WHERE id=?",
                             (
-                                new_name,
+                                &new_name,
+                                normalize_text(
+                                    if !new_name.is_empty() {
+                                        &new_name
+                                    } else {
+                                        &new_authname
+                                    }),
                                 if update_addr {
                                     addr.to_string()
                                 } else {
@@ -982,11 +1007,7 @@ impl Contact {
                                 } else {
                                     row_origin
                                 },
-                                if update_authname {
-                                    name.to_string()
-                                } else {
-                                    row_authname
-                                },
+                                &new_authname,
                                 row_id,
                             ),
                         )?;
@@ -998,18 +1019,18 @@ impl Contact {
                         sth_modified = Modifier::Modified;
                     }
                 } else {
-                    let update_name = manual;
-                    let update_authname = !manual;
-
                     transaction.execute(
-                        "INSERT INTO contacts (name, addr, fingerprint, origin, authname)
-                         VALUES (?, ?, ?, ?, ?);",
+                        "
+INSERT INTO contacts (name, name_normalized, addr, fingerprint, origin, authname)
+VALUES (?, ?, ?, ?, ?, ?)
+                        ",
                         (
-                            if update_name { &name } else { "" },
+                            if manual { &name } else { "" },
+                            normalize_text(&name),
                             &addr,
                             fingerprint,
                             origin,
-                            if update_authname { &name } else { "" },
+                            if manual { "" } else { &name },
                         ),
                     )?;
 
@@ -1112,17 +1133,19 @@ impl Contact {
             Origin::IncomingReplyTo
         };
         if query.is_some() {
-            let s3str_like_cmd = format!("%{}%", query.unwrap_or(""));
+            let s3str_like_cmd = format!("%{}%", query.unwrap_or("").to_lowercase());
             context
                 .sql
                 .query_map(
-                    "SELECT c.id, c.addr FROM contacts c
-                 WHERE c.id>?
-                 AND (c.fingerprint='')=?
-                 AND c.origin>=? \
-                 AND c.blocked=0 \
-                 AND (iif(c.name='',c.authname,c.name) LIKE ? OR c.addr LIKE ?) \
-                 ORDER BY c.last_seen DESC, c.id DESC;",
+                    "
+SELECT c.id, c.addr FROM contacts c
+WHERE c.id>?
+    AND (c.fingerprint='')=?
+    AND c.origin>=?
+    AND c.blocked=0
+    AND (IFNULL(c.name_normalized,IIF(c.name='',c.authname,c.name)) LIKE ? OR c.addr LIKE ?)
+ORDER BY c.last_seen DESC, c.id DESC
+                    ",
                     (
                         ContactId::LAST_SPECIAL,
                         flag_address,
@@ -1249,8 +1272,18 @@ impl Contact {
                     };
                     // Always do an update in case the blocking is reset or name is changed.
                     transaction.execute(
-                        "UPDATE contacts SET name=?, origin=?, blocked=1, fingerprint=? WHERE addr=?",
-                        (&name, Origin::MailinglistAddress, fingerprint, &grpid),
+                        "
+UPDATE contacts
+SET name=?, name_normalized=IIF(?1='',name_normalized,?), origin=?, blocked=1, fingerprint=?
+WHERE addr=?
+                        ",
+                        (
+                            &name,
+                            normalize_text(&name),
+                            Origin::MailinglistAddress,
+                            fingerprint,
+                            &grpid,
+                        ),
                     )?;
                 }
                 Ok(())
@@ -1725,8 +1758,8 @@ fn update_chat_names(
         };
 
         let count = transaction.execute(
-            "UPDATE chats SET name=?1 WHERE id=?2 AND name!=?1",
-            (chat_name, chat_id),
+            "UPDATE chats SET name=?1, name_normalized=?2 WHERE id=?3 AND name!=?1",
+            (&chat_name, normalize_text(&chat_name), chat_id),
         )?;
 
         if count > 0 {
diff --git a/src/contact/contact_tests.rs b/src/contact/contact_tests.rs
index 8c8804f0d8..700c88849b 100644
--- a/src/contact/contact_tests.rs
+++ b/src/contact/contact_tests.rs
@@ -60,16 +60,16 @@ async fn test_get_contacts() -> Result<()> {
     let context = tcm.bob().await;
     let alice = tcm.alice().await;
     alice
-        .set_config(Config::Displayname, Some("MyName"))
+        .set_config(Config::Displayname, Some("MyNameIsΔ"))
         .await?;
 
     // Alice is not in the contacts yet.
     let contacts = Contact::get_all(&context.ctx, 0, Some("Alice")).await?;
     assert_eq!(contacts.len(), 0);
-    let contacts = Contact::get_all(&context.ctx, 0, Some("MyName")).await?;
+    let contacts = Contact::get_all(&context.ctx, 0, Some("MyNameIsΔ")).await?;
     assert_eq!(contacts.len(), 0);
 
-    let claire_id = Contact::create(&context, "someone", "claire@example.org").await?;
+    let claire_id = Contact::create(&context, "Δ-someone", "claire@example.org").await?;
     let dave_id = Contact::create(&context, "", "dave@example.org").await?;
 
     let id = context.add_or_lookup_contact_id(&alice).await;
@@ -77,8 +77,8 @@ async fn test_get_contacts() -> Result<()> {
 
     let contact = Contact::get_by_id(&context, id).await.unwrap();
     assert_eq!(contact.get_name(), "");
-    assert_eq!(contact.get_authname(), "MyName");
-    assert_eq!(contact.get_display_name(), "MyName");
+    assert_eq!(contact.get_authname(), "MyNameIsΔ");
+    assert_eq!(contact.get_display_name(), "MyNameIsΔ");
 
     // Search by name.
     let contacts = Contact::get_all(&context, 0, Some("myname")).await?;
@@ -93,12 +93,12 @@ async fn test_get_contacts() -> Result<()> {
     let contacts = Contact::get_all(&context, 0, Some("Foobar")).await?;
     assert_eq!(contacts.len(), 0);
 
-    // Set Alice name to "someone" manually.
-    id.set_name(&context, "someone").await?;
+    // Set Alice name manually.
+    id.set_name(&context, "Δ-someone").await?;
     let contact = Contact::get_by_id(&context.ctx, id).await.unwrap();
-    assert_eq!(contact.get_name(), "someone");
-    assert_eq!(contact.get_authname(), "MyName");
-    assert_eq!(contact.get_display_name(), "someone");
+    assert_eq!(contact.get_name(), "Δ-someone");
+    assert_eq!(contact.get_authname(), "MyNameIsΔ");
+    assert_eq!(contact.get_display_name(), "Δ-someone");
 
     // Not searchable by authname, because it is not displayed.
     let contacts = Contact::get_all(&context, 0, Some("MyName")).await?;
@@ -108,7 +108,9 @@ async fn test_get_contacts() -> Result<()> {
         info!(&context, "add_self={add_self}");
 
         // Search key-contacts by display name (same as manually set name).
-        let contacts = Contact::get_all(&context.ctx, add_self, Some("someone")).await?;
+        let contacts = Contact::get_all(&context.ctx, add_self, Some("Δ-someone")).await?;
+        assert_eq!(contacts, vec![id]);
+        let contacts = Contact::get_all(&context.ctx, add_self, Some("δ-someon")).await?;
         assert_eq!(contacts, vec![id]);
 
         // Get all key-contacts.
@@ -120,7 +122,7 @@ async fn test_get_contacts() -> Result<()> {
     }
 
     // Search address-contacts by display name.
-    let contacts = Contact::get_all(&context, constants::DC_GCL_ADDRESS, Some("someone")).await?;
+    let contacts = Contact::get_all(&context, constants::DC_GCL_ADDRESS, Some("Δ-someone")).await?;
     assert_eq!(contacts, vec![claire_id]);
 
     // Get all address-contacts. Newer contacts go first.
@@ -134,6 +136,16 @@ async fn test_get_contacts() -> Result<()> {
     .await?;
     assert_eq!(contacts, vec![dave_id, claire_id, ContactId::SELF]);
 
+    // Reset the user-provided name for Alice.
+    id.set_name(&context, "").await?;
+    let contact = Contact::get_by_id(&context.ctx, id).await.unwrap();
+    assert_eq!(contact.get_name(), "");
+    assert_eq!(contact.get_authname(), "MyNameIsΔ");
+    assert_eq!(contact.get_display_name(), "MyNameIsΔ");
+    let contacts = Contact::get_all(&context, 0, Some("MyName")).await?;
+    assert_eq!(contacts.len(), 1);
+    let contacts = Contact::get_all(&context, 0, Some("δ")).await?;
+    assert_eq!(contacts.len(), 1);
     Ok(())
 }
 
diff --git a/src/message.rs b/src/message.rs
index aedfded94a..8dd19c11ec 100644
--- a/src/message.rs
+++ b/src/message.rs
@@ -2248,14 +2248,5 @@ impl Viewtype {
     }
 }
 
-/// Returns text for storing in the `msgs.txt_normalized` column (to make case-insensitive search
-/// possible for non-ASCII messages).
-pub(crate) fn normalize_text(text: &str) -> Option<String> {
-    if text.is_ascii() {
-        return None;
-    };
-    Some(text.to_lowercase()).filter(|t| t != text)
-}
-
 #[cfg(test)]
 mod message_tests;
diff --git a/src/receive_imf.rs b/src/receive_imf.rs
index 35dfbcbc9e..2483652928 100644
--- a/src/receive_imf.rs
+++ b/src/receive_imf.rs
@@ -43,7 +43,9 @@ use crate::simplify;
 use crate::stats::STATISTICS_BOT_EMAIL;
 use crate::stock_str;
 use crate::sync::Sync::*;
-use crate::tools::{self, buf_compress, remove_subject_prefix, validate_broadcast_secret};
+use crate::tools::{
+    self, buf_compress, normalize_text, remove_subject_prefix, validate_broadcast_secret,
+};
 use crate::{chatlist_events, ensure_and_debug_assert, ensure_and_debug_assert_eq, location};
 
 /// This is the struct that is returned after receiving one email (aka MIME message).
@@ -2094,7 +2096,7 @@ RETURNING id
                     if trash { MessageState::Undefined } else { state },
                     if trash { MessengerMessage::No } else { is_dc_message },
                     if trash || hidden { "" } else { msg },
-                    if trash || hidden { None } else { message::normalize_text(msg) },
+                    if trash || hidden { None } else { normalize_text(msg) },
                     if trash || hidden { "" } else { &subject },
                     if trash {
                         "".to_string()
@@ -3091,7 +3093,10 @@ async fn apply_chat_name_and_avatar_changes(
             info!(context, "Updating grpname for chat {}.", chat.id);
             context
                 .sql
-                .execute("UPDATE chats SET name=? WHERE id=?;", (grpname, chat.id))
+                .execute(
+                    "UPDATE chats SET name=?, name_normalized=? WHERE id=?",
+                    (grpname, normalize_text(grpname), chat.id),
+                )
                 .await?;
             *send_event_chat_modified = true;
         }
@@ -3380,7 +3385,10 @@ async fn apply_mailinglist_changes(
         info!(context, "Updating listname for chat {chat_id}.");
         context
             .sql
-            .execute("UPDATE chats SET name=? WHERE id=?;", (new_name, chat_id))
+            .execute(
+                "UPDATE chats SET name=?, name_normalized=? WHERE id=?",
+                (&new_name, normalize_text(&new_name), chat_id),
+            )
             .await?;
         context.emit_event(EventType::ChatModified(chat_id));
     }
diff --git a/src/sql/migrations.rs b/src/sql/migrations.rs
index 8a5eb4d59e..198eb8081d 100644
--- a/src/sql/migrations.rs
+++ b/src/sql/migrations.rs
@@ -19,7 +19,7 @@ use crate::log::warn;
 use crate::message::MsgId;
 use crate::provider::get_provider_info;
 use crate::sql::Sql;
-use crate::tools::{Time, inc_and_check, time_elapsed};
+use crate::tools::{Time, inc_and_check, normalize_text, time_elapsed};
 use crate::transport::ConfiguredLoginParam;
 
 const DBVERSION: i32 = 68;
@@ -1454,6 +1454,56 @@ CREATE INDEX imap_sync_index ON imap_sync(transport_id, folder);
         .await?;
     }
 
+    inc_and_check(&mut migration_version, 143)?;
+    if dbversion < migration_version {
+        let trans_fn = |t: &mut rusqlite::Transaction| {
+            t.execute_batch(
+                "
+ALTER TABLE chats ADD COLUMN name_normalized TEXT;
+ALTER TABLE contacts ADD COLUMN name_normalized TEXT;
+                ",
+            )?;
+
+            let mut stmt = t.prepare("UPDATE chats SET name_normalized=? WHERE id=?")?;
+            for res in t
+                .prepare("SELECT id, name FROM chats LIMIT 10000")?
+                .query_map((), |row| {
+                    let id: u32 = row.get(0)?;
+                    let name: String = row.get(1)?;
+                    Ok((id, name))
+                })?
+            {
+                let (id, name) = res?;
+                if let Some(name_normalized) = normalize_text(&name) {
+                    stmt.execute((name_normalized, id))?;
+                }
+            }
+
+            let mut stmt = t.prepare("UPDATE contacts SET name_normalized=? WHERE id=?")?;
+            for res in t
+                .prepare(
+                    "
+SELECT id, IIF(name='', authname, name) FROM contacts
+ORDER BY last_seen DESC LIMIT 10000
+                ",
+                )?
+                .query_map((), |row| {
+                    let id: u32 = row.get(0)?;
+                    let name: String = row.get(1)?;
+                    Ok((id, name))
+                })?
+            {
+                let (id, name) = res?;
+                if let Some(name_normalized) = normalize_text(&name) {
+                    stmt.execute((name_normalized, id))?;
+                }
+            }
+            Ok(())
+        };
+        sql.execute_migration_transaction(trans_fn, migration_version)
+            .await?;
+    }
+
     let new_version = sql
         .get_raw_config_int(VERSION_CFG)
         .await?
diff --git a/src/sql/migrations/migrations_tests.rs b/src/sql/migrations/migrations_tests.rs
index 0517f12e51..1e0df73cd5 100644
--- a/src/sql/migrations/migrations_tests.rs
+++ b/src/sql/migrations/migrations_tests.rs
@@ -160,9 +160,7 @@ async fn test_key_contacts_migration_verified() -> Result<()> {
     "#,
     )?)).await?;
 
-    STOP_MIGRATIONS_AT
-        .scope(133, t.sql.run_migrations(&t))
-        .await?;
+    t.sql.run_migrations(&t).await?;
 
     // Hidden address-contact can't be looked up.
     assert!(
diff --git a/src/tools.rs b/src/tools.rs
index 48363eabe7..b9c1e15401 100644
--- a/src/tools.rs
+++ b/src/tools.rs
@@ -779,6 +779,15 @@ pub(crate) fn to_lowercase(s: &str) -> Cow<'_, str> {
     }
 }
 
+/// Returns text for storing in special db columns to make case-insensitive search possible for
+/// non-ASCII messages, chat and contact names.
+pub(crate) fn normalize_text(text: &str) -> Option<String> {
+    if text.is_ascii() {
+        return None;
+    };
+    Some(text.to_lowercase()).filter(|t| t != text)
+}
+
 /// Increments `*t` and checks that it equals to `expected` after that.
 pub(crate) fn inc_and_check<T: PrimInt + AddAssign + std::fmt::Debug>(
     t: &mut T,