diff --git a/src/channel.cpp b/src/channel.cpp
index 3e214bb34..f72a0a01d 100644
--- a/src/channel.cpp
+++ b/src/channel.cpp
@@ -22,11 +22,19 @@ Channel::Channel(const QString &_name)
     : name(_name)
     , completionModel(this->name)
 {
+    this->clearCompletionModelTimer = new QTimer;
+    QObject::connect(this->clearCompletionModelTimer, &QTimer::timeout, [this]() {
+        this->completionModel.ClearExpiredStrings();  //
+    });
+    this->clearCompletionModelTimer->start(60 * 1000);
 }
 
 Channel::~Channel()
 {
     this->destroyed.invoke();
+
+    this->clearCompletionModelTimer->stop();
+    this->clearCompletionModelTimer->deleteLater();
 }
 
 bool Channel::isEmpty() const
diff --git a/src/channel.hpp b/src/channel.hpp
index f7993c7f4..ca51c7c27 100644
--- a/src/channel.hpp
+++ b/src/channel.hpp
@@ -7,6 +7,7 @@
 #include "util/concurrentmap.hpp"
 
 #include <QString>
+#include <QTimer>
 #include <boost/signals2.hpp>
 
 #include <memory>
@@ -18,6 +19,8 @@ struct Message;
 
 class Channel : public std::enable_shared_from_this<Channel>
 {
+    QTimer *clearCompletionModelTimer;
+
 public:
     explicit Channel(const QString &_name);
     virtual ~Channel();
diff --git a/src/util/completionmodel.cpp b/src/util/completionmodel.cpp
index a13b917f1..0bef743b1 100644
--- a/src/util/completionmodel.cpp
+++ b/src/util/completionmodel.cpp
@@ -81,12 +81,13 @@ void CompletionModel::refresh()
 
 void CompletionModel::addString(const std::string &str, TaggedString::Type type)
 {
-    // Always add a space at the end of completions
-    this->emotes.insert({qS(str + " "), type});
+    this->addString(qS(str), type);
 }
 
 void CompletionModel::addString(const QString &str, TaggedString::Type type)
 {
+    std::lock_guard<std::mutex> lock(this->emotesMutex);
+
     // Always add a space at the end of completions
     this->emotes.insert({str + " ", type});
 }
@@ -108,4 +109,22 @@ void CompletionModel::addUser(const QString &str)
     }
 }
 
+void CompletionModel::ClearExpiredStrings()
+{
+    std::lock_guard<std::mutex> lock(this->emotesMutex);
+
+    auto now = std::chrono::steady_clock::now();
+
+    for (auto it = this->emotes.begin(); it != this->emotes.end();) {
+        const auto &taggedString = *it;
+
+        if (taggedString.HasExpired(now)) {
+            // debug::Log("String {} expired", taggedString.str);
+            it = this->emotes.erase(it);
+        } else {
+            ++it;
+        }
+    }
+}
+
 }  // namespace chatterino
diff --git a/src/util/completionmodel.hpp b/src/util/completionmodel.hpp
index b804b5246..629f5dd15 100644
--- a/src/util/completionmodel.hpp
+++ b/src/util/completionmodel.hpp
@@ -4,6 +4,8 @@
 
 #include <QAbstractListModel>
 
+#include <chrono>
+#include <mutex>
 #include <set>
 #include <string>
 
@@ -12,9 +14,6 @@ namespace chatterino {
 class CompletionModel : public QAbstractListModel
 {
     struct TaggedString {
-        QString str;
-
-        // Type will help decide the lifetime of the tagged strings
         enum Type {
             Username,
 
@@ -26,7 +25,38 @@ class CompletionModel : public QAbstractListModel
             TwitchGlobalEmote,
             TwitchSubscriberEmote,
             Emoji,
-        } type;
+        };
+
+        TaggedString(const QString &_str, Type _type)
+            : str(_str)
+            , type(_type)
+            , timeAdded(std::chrono::steady_clock::now())
+        {
+        }
+
+        QString str;
+
+        // Type will help decide the lifetime of the tagged strings
+        Type type;
+
+        std::chrono::steady_clock::time_point timeAdded;
+
+        bool HasExpired(const std::chrono::steady_clock::time_point &now) const
+        {
+            switch (this->type) {
+                case Type::Username: {
+                    static std::chrono::minutes expirationTimer(10);
+
+                    return (this->timeAdded + expirationTimer < now);
+                } break;
+
+                default: {
+                    return false;
+                } break;
+            }
+
+            return false;
+        }
 
         bool IsEmote() const
         {
@@ -40,45 +70,49 @@ class CompletionModel : public QAbstractListModel
                     int k = QString::compare(this->str, that.str, Qt::CaseInsensitive);
                     if (k == 0) {
                         return this->str > that.str;
-                    } else {
-                        return k < 0;
-                    }
-                } else {
-                    return true;
-                }
-            } else {
-                if (that.IsEmote()) {
-                    return false;
-                } else {
-                    int k = QString::compare(this->str, that.str, Qt::CaseInsensitive);
-                    if (k == 0) {
-                        return false;
-                    } else {
-                        return k < 0;
                     }
+
+                    return k < 0;
                 }
+
+                return true;
             }
+
+            if (that.IsEmote()) {
+                return false;
+            }
+
+            int k = QString::compare(this->str, that.str, Qt::CaseInsensitive);
+            if (k == 0) {
+                return false;
+            }
+
+            return k < 0;
         }
     };
 
 public:
     CompletionModel(const QString &_channelName);
 
-    virtual int columnCount(const QModelIndex &) const override
+    int columnCount(const QModelIndex &) const override
     {
         return 1;
     }
 
-    virtual QVariant data(const QModelIndex &index, int) const override
+    QVariant data(const QModelIndex &index, int) const override
     {
+        std::lock_guard<std::mutex> lock(this->emotesMutex);
+
         // TODO: Implement more safely
         auto it = this->emotes.begin();
         std::advance(it, index.row());
         return QVariant(it->str);
     }
 
-    virtual int rowCount(const QModelIndex &) const override
+    int rowCount(const QModelIndex &) const override
     {
+        std::lock_guard<std::mutex> lock(this->emotesMutex);
+
         return this->emotes.size();
     }
 
@@ -88,12 +122,15 @@ public:
 
     void addUser(const QString &str);
 
+    void ClearExpiredStrings();
+
 private:
     TaggedString createUser(const QString &str)
     {
         return TaggedString{str, TaggedString::Type::Username};
     }
 
+    mutable std::mutex emotesMutex;
     std::set<TaggedString> emotes;
 
     QString channelName;