--- taglib/toolkit/tlist.h
+++ taglib/toolkit/tlist.h
@@ -226,6 +226,7 @@
      * the same.
      */
     bool operator==(const List<T> &l) const;
+    bool operator!=(const List<T> &l) const;
 
   protected:
     /*
--- taglib/toolkit/tlist.tcc
+++ taglib/toolkit/tlist.tcc
@@ -300,6 +300,12 @@
   return d->list == l.d->list;
 }
 
+template <class T>
+bool List<T>::operator!=(const List<T> &l) const
+{
+  return !operator==(l);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // protected members
 ////////////////////////////////////////////////////////////////////////////////
--- taglib/toolkit/tstring.h
+++ taglib/toolkit/tstring.h
@@ -342,6 +342,7 @@
      * returns true if the strings match.
      */
     bool operator==(const String &s) const;
+    bool operator!=(const String &s) const;
 
     /*!
      * Appends \a s to the end of the String.
--- taglib/toolkit/tstring.cpp
+++ taglib/toolkit/tstring.cpp
@@ -546,6 +546,11 @@
   return d == s.d || d->data == s.d->data;
 }
 
+bool String::operator!=(const String &s) const
+{
+  return !operator==(s);
+}
+
 String &String::operator+=(const String &s)
 {
   detach();