diff --git a/src/plugins/todo/keyworddialog.cpp b/src/plugins/todo/keyworddialog.cpp
index 898ccdd403e..6ec25477f0f 100644
--- a/src/plugins/todo/keyworddialog.cpp
+++ b/src/plugins/todo/keyworddialog.cpp
@@ -41,14 +41,20 @@
 namespace Todo {
 namespace Internal {
 
-KeywordDialog::KeywordDialog(const Keyword &keyword, QWidget *parent) :
+KeywordDialog::KeywordDialog(const Keyword &keyword, const QSet<QString> &alreadyUsedKeywordNames,
+                             QWidget *parent) :
     QDialog(parent),
-    ui(new Ui::AddKeywordDialog)
+    ui(new Ui::KeywordDialog),
+    m_alreadyUsedKeywordNames(alreadyUsedKeywordNames)
 {
     ui->setupUi(this);
     setupListWidget(keyword.iconResource);
     setupColorWidgets(keyword.color);
     ui->keywordNameEdit->setText(keyword.name);
+    ui->errorLabel->hide();
+
+    connect(ui->buttonBox, SIGNAL(accepted()), SLOT(acceptButtonClicked()));
+    connect(ui->keywordNameEdit, SIGNAL(textChanged(QString)), ui->errorLabel, SLOT(hide()));
 }
 
 KeywordDialog::~KeywordDialog()
@@ -59,7 +65,7 @@ KeywordDialog::~KeywordDialog()
 Keyword KeywordDialog::keyword()
 {
     Keyword result;
-    result.name = ui->keywordNameEdit->text();
+    result.name = keywordName();
     result.iconResource = ui->listWidget->currentItem()->data(Qt::UserRole).toString();
     result.color = ui->colorEdit->text();
 
@@ -71,6 +77,12 @@ void KeywordDialog::colorSelected(const QColor &color)
     ui->colorEdit->setText(color.name());
 }
 
+void KeywordDialog::acceptButtonClicked()
+{
+    if (canAccept())
+        accept();
+}
+
 void KeywordDialog::setupListWidget(const QString &selectedIcon)
 {
     ui->listWidget->setViewMode(QListWidget::IconMode);
@@ -109,5 +121,52 @@ void KeywordDialog::setupColorWidgets(const QColor &color)
     connect(ui->colorButton, SIGNAL(colorChanged(QColor)), SLOT(colorSelected(QColor)));
 }
 
+bool KeywordDialog::canAccept()
+{
+    if (!isKeywordNameCorrect()) {
+        showError(tr("Keyword cannot be empty, contain spaces or colons."));
+        return false;
+    }
+
+    if (isKeywordNameAlreadyUsed()) {
+        showError(tr("There is already a keyword with this name."));
+        return false;
+    }
+
+    return true;
+}
+
+bool KeywordDialog::isKeywordNameCorrect()
+{
+    // Make sure keyword is not empty and contains no spaces or colons
+
+    QString name = keywordName();
+
+    if (name.isEmpty())
+        return false;
+
+    for (int i = 0; i < name.size(); ++i)
+        if (name.at(i).isSpace() || name.at(i) == QLatin1Char(':'))
+            return false;
+
+    return true;
+}
+
+bool KeywordDialog::isKeywordNameAlreadyUsed()
+{
+    return m_alreadyUsedKeywordNames.contains(keywordName());
+}
+
+void KeywordDialog::showError(const QString &text)
+{
+    ui->errorLabel->setText(text);
+    ui->errorLabel->show();
+}
+
+QString KeywordDialog::keywordName()
+{
+    return ui->keywordNameEdit->text().trimmed();
+}
+
 } // namespace Internal
 } // namespace Todo
diff --git a/src/plugins/todo/keyworddialog.h b/src/plugins/todo/keyworddialog.h
index d4226751e28..7db252613cc 100644
--- a/src/plugins/todo/keyworddialog.h
+++ b/src/plugins/todo/keyworddialog.h
@@ -31,16 +31,17 @@
 **
 **************************************************************************/
 
-#ifndef ADDKEYWORDDIALOG_H
-#define ADDKEYWORDDIALOG_H
+#ifndef KEYWORDDIALOG_H
+#define KEYWORDDIALOG_H
 
 #include <QDialog>
+#include <QSet>
 
 namespace Todo {
 namespace Internal {
 
 namespace Ui {
-    class AddKeywordDialog;
+    class KeywordDialog;
 }
 
 class Keyword;
@@ -49,21 +50,30 @@ class KeywordDialog : public QDialog
 {
     Q_OBJECT
 public:
-    KeywordDialog(const Keyword &keyword, QWidget *parent = 0);
+    KeywordDialog(const Keyword &keyword, const QSet<QString> &alreadyUsedKeywordNames,
+                  QWidget *parent = 0);
     ~KeywordDialog();
 
     Keyword keyword();
 
 private slots:
     void colorSelected(const QColor &color);
+    void acceptButtonClicked();
 
 private:
     void setupListWidget(const QString &selectedIcon);
     void setupColorWidgets(const QColor &color);
-    Ui::AddKeywordDialog *ui;
+    bool canAccept();
+    bool isKeywordNameCorrect();
+    bool isKeywordNameAlreadyUsed();
+    void showError(const QString &text);
+    QString keywordName();
+
+    Ui::KeywordDialog *ui;
+    QSet<QString> m_alreadyUsedKeywordNames;
 };
 
 } // namespace Internal
 } // namespace Todo
 
-#endif // ADDKEYWORDDIALOG_H
+#endif // KEYWORDDIALOG_H
diff --git a/src/plugins/todo/keyworddialog.ui b/src/plugins/todo/keyworddialog.ui
index 8d73589f128..13516dc99e0 100644
--- a/src/plugins/todo/keyworddialog.ui
+++ b/src/plugins/todo/keyworddialog.ui
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
- <class>Todo::Internal::AddKeywordDialog</class>
- <widget class="QDialog" name="Todo::Internal::AddKeywordDialog">
+ <class>Todo::Internal::KeywordDialog</class>
+ <widget class="QDialog" name="Todo::Internal::KeywordDialog">
   <property name="geometry">
    <rect>
     <x>0</x>
@@ -79,6 +79,16 @@
      </item>
     </layout>
    </item>
+   <item>
+    <widget class="QLabel" name="errorLabel">
+     <property name="styleSheet">
+      <string notr="true">color: red;</string>
+     </property>
+     <property name="text">
+      <string>errorLabel</string>
+     </property>
+    </widget>
+   </item>
    <item>
     <widget class="QDialogButtonBox" name="buttonBox">
      <property name="orientation">
@@ -100,26 +110,10 @@
  </customwidgets>
  <resources/>
  <connections>
-  <connection>
-   <sender>buttonBox</sender>
-   <signal>accepted()</signal>
-   <receiver>Todo::Internal::AddKeywordDialog</receiver>
-   <slot>accept()</slot>
-   <hints>
-    <hint type="sourcelabel">
-     <x>248</x>
-     <y>254</y>
-    </hint>
-    <hint type="destinationlabel">
-     <x>157</x>
-     <y>274</y>
-    </hint>
-   </hints>
-  </connection>
   <connection>
    <sender>buttonBox</sender>
    <signal>rejected()</signal>
-   <receiver>Todo::Internal::AddKeywordDialog</receiver>
+   <receiver>Todo::Internal::KeywordDialog</receiver>
    <slot>reject()</slot>
    <hints>
     <hint type="sourcelabel">
diff --git a/src/plugins/todo/optionsdialog.cpp b/src/plugins/todo/optionsdialog.cpp
index e6432967eb4..5c9d643e790 100644
--- a/src/plugins/todo/optionsdialog.cpp
+++ b/src/plugins/todo/optionsdialog.cpp
@@ -71,6 +71,17 @@ void OptionsDialog::addToKeywordsList(const Keyword &keyword)
     ui->keywordsList->addItem(item);
 }
 
+QSet<QString> OptionsDialog::keywordNames()
+{
+    KeywordList keywords = settingsFromUi().keywords;
+
+    QSet<QString> result;
+    foreach (const Keyword &keyword, keywords)
+        result << keyword.name;
+
+    return result;
+}
+
 Settings OptionsDialog::settings()
 {
     return settingsFromUi();
@@ -79,9 +90,9 @@ Settings OptionsDialog::settings()
 void OptionsDialog::addButtonClicked()
 {
     Keyword keyword;
-    KeywordDialog *addKeywordDialog = new KeywordDialog(keyword, this);
-    if (addKeywordDialog->exec() == QDialog::Accepted) {
-        keyword = addKeywordDialog->keyword();
+    KeywordDialog *keywordDialog = new KeywordDialog(keyword, keywordNames(), this);
+    if (keywordDialog->exec() == QDialog::Accepted) {
+        keyword = keywordDialog->keyword();
         addToKeywordsList(keyword);
     }
 }
@@ -95,9 +106,12 @@ void OptionsDialog::editButtonClicked()
     keyword.iconResource = item->data(Qt::UserRole).toString();
     keyword.color = item->backgroundColor();
 
-    KeywordDialog *addKeywordDialog = new KeywordDialog(keyword, this);
-    if (addKeywordDialog->exec() == QDialog::Accepted) {
-        keyword = addKeywordDialog->keyword();
+    QSet<QString> keywordNamesButThis = keywordNames();
+    keywordNamesButThis.remove(keyword.name);
+
+    KeywordDialog *keywordDialog = new KeywordDialog(keyword, keywordNamesButThis, this);
+    if (keywordDialog->exec() == QDialog::Accepted) {
+        keyword = keywordDialog->keyword();
         item->setIcon(QIcon(keyword.iconResource));
         item->setText(keyword.name);
         item->setData(Qt::UserRole, keyword.iconResource);
diff --git a/src/plugins/todo/optionsdialog.h b/src/plugins/todo/optionsdialog.h
index 5a876e8e626..6867de7c07b 100644
--- a/src/plugins/todo/optionsdialog.h
+++ b/src/plugins/todo/optionsdialog.h
@@ -67,6 +67,7 @@ private:
     void uiFromSettings(const Settings &settings);
     Settings settingsFromUi();
     void addToKeywordsList(const Keyword &keyword);
+    QSet<QString> keywordNames();
 
     Ui::OptionsDialog *ui;
 };