diff --git a/kcms/fonts/fontsaasettings.h b/kcms/fonts/fontsaasettings.h
--- a/kcms/fonts/fontsaasettings.h
+++ b/kcms/fonts/fontsaasettings.h
@@ -50,9 +50,9 @@
     void setExclude(bool exclude);
     void setExcludeFrom(int excludeFrom);
     void setExcludeTo(int excludeTo);
-    void setAntiAliasing(bool antiAliasing);
+    void setAntiAliasing(bool enabled);
     void setDpi(int dpi);
-    void setSubPixel(KXftConfig::SubPixel::Type subPixel);
+    void setSubPixel(KXftConfig::SubPixel::Type type);
     void setHinting(KXftConfig::Hint::Style hinting);
 
 signals:
diff --git a/kcms/fonts/fontsaasettings.cpp b/kcms/fonts/fontsaasettings.cpp
--- a/kcms/fonts/fontsaasettings.cpp
+++ b/kcms/fonts/fontsaasettings.cpp
@@ -44,12 +44,12 @@
         return true;
     }
 
-    int defaultSubPixel()
+    KXftConfig::SubPixel::Type defaultSubPixel()
     {
         return KXftConfig::SubPixel::Rgb;
     }
 
-    int defaultHinting()
+    KXftConfig::Hint::Style defaultHinting()
     {
         return KXftConfig::Hint::Slight;
     }
@@ -80,7 +80,9 @@
 
     void setExclude(bool exclude)
     {
-        m_exclude = exclude;
+        if (m_exclude != exclude) {
+            m_exclude = exclude;
+        }
     }
 
     int excludeFrom() const
@@ -90,7 +92,9 @@
 
     void setExcludeFrom(int excludeFrom)
     {
-        m_excludeFrom = excludeFrom;
+        if (m_excludeFrom != excludeFrom) {
+            m_excludeFrom = excludeFrom;
+        }
     }
 
     int excludeTo() const
@@ -100,7 +104,9 @@
 
     void setExcludeTo(int excludeTo)
     {
-        m_excludeTo = excludeTo;
+        if (m_excludeTo != excludeTo) {
+            m_excludeTo = excludeTo;
+        }
     }
 
     bool antiAliasing() const
@@ -112,8 +118,8 @@
     {
         if (antiAliasing != m_antiAliasing) {
             m_antiAliasingChanged = true;
+            m_antiAliasing = antiAliasing;
         }
-        m_antiAliasing = antiAliasing;
     }
 
     KXftConfig::SubPixel::Type subPixel() const
@@ -123,7 +129,10 @@
 
     void setSubPixel(KXftConfig::SubPixel::Type subPixel)
     {
-        m_subPixel = subPixel;
+        if (m_subPixel != subPixel) {
+            m_subPixelChanged = true;
+            m_subPixel = subPixel;
+        }
     }
 
     KXftConfig::Hint::Style hinting() const
@@ -133,7 +142,10 @@
 
     void setHinting(KXftConfig::Hint::Style hinting)
     {
-        m_hinting = hinting;
+        if (m_hinting != hinting) {
+            m_hintingChanged = true;
+            m_hinting = hinting;
+        }
     }
 
     void save()
@@ -151,35 +163,33 @@
             xft.setExcludeRange(0, 0);
         }
 
-        KXftConfig::SubPixel::Type spType = static_cast<KXftConfig::SubPixel::Type>(m_subPixel);
         if (m_subPixelChanged || xft.subPixelTypeHasLocalConfig()) {
-            xft.setSubPixelType(spType);
+            xft.setSubPixelType(m_subPixel);
         } else {
             xft.setSubPixelType(KXftConfig::SubPixel::NotSet);
         }
 
-        KXftConfig::Hint::Style hStyle = static_cast<KXftConfig::Hint::Style>(m_hinting);
         if (m_hintingChanged || xft.hintStyleHasLocalConfig()) {
-            xft.setHintStyle(hStyle);
+            xft.setHintStyle(m_hinting);
         } else {
             xft.setHintStyle(KXftConfig::Hint::NotSet);
         }
 
         // Write to KConfig to sync with krdb
         KSharedConfig::Ptr config = KSharedConfig::openConfig("kdeglobals");
         KConfigGroup grp(config, "General");
 
-        grp.writeEntry("XftSubPixel", KXftConfig::toStr(spType));
+        grp.writeEntry("XftSubPixel", KXftConfig::toStr(m_subPixel));
 
         if (aaState == KXftConfig::AntiAliasing::NotSet) {
            grp.revertToDefault("XftAntialias");
         } else {
             grp.writeEntry("XftAntialias", aaState == KXftConfig::AntiAliasing::Enabled);
         }
 
-        QString hs(KXftConfig::toStr(hStyle));
+        QString hs(KXftConfig::toStr(m_hinting));
         if (hs != grp.readEntry("XftHintStyle")) {
-            if (KXftConfig::Hint::NotSet == hStyle) {
+            if (KXftConfig::Hint::NotSet == m_hinting) {
                 grp.revertToDefault("XftHintStyle");
             } else {
                 grp.writeEntry("XftHintStyle", hs);
@@ -307,9 +317,18 @@
     return findItem("antiAliasing")->property().toBool();
 }
 
-void FontsAASettings::setAntiAliasing(bool antiAliasing)
+void FontsAASettings::setAntiAliasing(bool enabled)
 {
-    findItem("antiAliasing")->setProperty(antiAliasing);
+    if (antiAliasing() == enabled) {
+        return;
+    }
+
+    findItem("antiAliasing")->setProperty(enabled);
+    if (!enabled) {
+        setSubPixel(KXftConfig::SubPixel::None);
+    } else if (subPixel() == KXftConfig::SubPixel::None) {
+        setSubPixel(defaultSubPixel());
+    }
 }
 
 int FontsAASettings::dpi() const
@@ -339,9 +358,16 @@
     return findItem("subPixel")->property().value<KXftConfig::SubPixel::Type>();
 }
 
-void FontsAASettings::setSubPixel(KXftConfig::SubPixel::Type subPixel)
+void FontsAASettings::setSubPixel(KXftConfig::SubPixel::Type type)
 {
-    findItem("subPixel")->setProperty(subPixel);
+    if (subPixel() == type) {
+        return;
+    }
+
+    findItem("subPixel")->setProperty(type);
+    if (type == KXftConfig::SubPixel::None) {
+        setAntiAliasing(false);
+    }
 }
 
 KXftConfig::Hint::Style FontsAASettings::hinting() const