diff --git a/src/spellcheck/ontheflycheck.h b/src/spellcheck/ontheflycheck.h
--- a/src/spellcheck/ontheflycheck.h
+++ b/src/spellcheck/ontheflycheck.h
@@ -119,6 +119,8 @@
 
 protected Q_SLOTS:
     void performSpellCheck();
+    void addToDictionary(const QString &word);
+    void addToSession(const QString &word);
     void misspelling(const QString &word, int start);
     void spellCheckDone();
 
diff --git a/src/spellcheck/ontheflycheck.cpp b/src/spellcheck/ontheflycheck.cpp
--- a/src/spellcheck/ontheflycheck.cpp
+++ b/src/spellcheck/ontheflycheck.cpp
@@ -401,11 +401,32 @@
                 this,
                 SLOT(misspelling(QString,int)));
         connect(m_backgroundChecker, SIGNAL(done()), this, SLOT(spellCheckDone()));
+
+        KateSpellCheckManager *m_spellCheckManager = KTextEditor::EditorPrivate::self()->spellCheckManager();
+        connect(m_spellCheckManager, &KateSpellCheckManager::wordAddedToDictionary,
+                this, &KateOnTheFlyChecker::addToDictionary);
+        connect(m_spellCheckManager, &KateSpellCheckManager::wordIgnored,
+                this, &KateOnTheFlyChecker::addToSession);
     }
     m_backgroundChecker->setSpeller(m_speller);
     m_backgroundChecker->setText(text); // don't call 'start()' after this!
 }
 
+void KateOnTheFlyChecker::addToDictionary(const QString &word)
+{
+    if (m_backgroundChecker) {
+        m_backgroundChecker->addWordToPersonal(word);
+    }
+}
+
+void KateOnTheFlyChecker::addToSession(const QString &word)
+{
+    if (m_backgroundChecker) {
+        m_backgroundChecker->addWordToSession(word);
+    }
+}
+
+
 void KateOnTheFlyChecker::removeRangeFromEverything(KTextEditor::MovingRange *movingRange)
 {
     Q_ASSERT(m_document == movingRange->document());
diff --git a/src/spellcheck/spellcheck.h b/src/spellcheck/spellcheck.h
--- a/src/spellcheck/spellcheck.h
+++ b/src/spellcheck/spellcheck.h
@@ -52,6 +52,14 @@
      **/
     static QList<KTextEditor::Range> rangeDifference(const KTextEditor::Range &r1, const KTextEditor::Range &r2);
 
+Q_SIGNALS:
+    /**
+     * These signals are used to propagate the dictionary changes to the
+     * BackgroundChecker instance in other components (e.g. onTheFlyChecker).
+     */
+    void wordAddedToDictionary(const QString &word);
+    void wordIgnored(const QString &word);
+
 public:
     QList<QPair<KTextEditor::Range, QString> > spellCheckLanguageRanges(KTextEditor::DocumentPrivate *doc, const KTextEditor::Range &range);
 
diff --git a/src/spellcheck/spellcheck.cpp b/src/spellcheck/spellcheck.cpp
--- a/src/spellcheck/spellcheck.cpp
+++ b/src/spellcheck/spellcheck.cpp
@@ -56,13 +56,15 @@
     Sonnet::Speller speller;
     speller.setLanguage(dictionary);
     speller.addToSession(word);
+    emit wordIgnored(word);
 }
 
 void KateSpellCheckManager::addToDictionary(const QString &word, const QString &dictionary)
 {
     Sonnet::Speller speller;
     speller.setLanguage(dictionary);
     speller.addToPersonal(word);
+    emit wordAddedToDictionary(word);
 }
 
 QList<KTextEditor::Range> KateSpellCheckManager::rangeDifference(const KTextEditor::Range &r1,