diff --git a/src/domain.cpp b/src/domain.cpp
index 081ba76..f2969e7 100644
--- a/src/domain.cpp
+++ b/src/domain.cpp
@@ -42,4 +42,18 @@ Domain Domain::subDomain(const QRectF& rect, qreal maxWidth,qreal maxHeight) con
 
   return domain;
 }
+
+bool operator== (const Domain &domain1, const Domain &domain2)
+{
+    return (domain1.m_maxX == domain2.m_maxX &&
+            domain1.m_maxY == domain2.m_maxY &&
+            domain1.m_minX == domain2.m_minX &&
+            domain1.m_minY == domain2.m_minY);
+}
+
+bool operator!= (const Domain &domain1, const Domain &domain2)
+{
+    return !(domain1 == domain2);
+}
+
 QTCOMMERCIALCHART_END_NAMESPACE
diff --git a/src/domain_p.h b/src/domain_p.h
index ea1998d..c60f8db 100644
--- a/src/domain_p.h
+++ b/src/domain_p.h
@@ -13,6 +13,9 @@ public:
 	qreal spanX() const;
 	qreal spanY() const;
 
+	friend bool operator== (const Domain &domain1, const Domain &domain2);
+	friend bool operator!= (const Domain &domain1, const Domain &domain2);
+
 	Domain subDomain(const QRectF& rect, qreal maxWidth, qreal maxHeight) const;
 
 public: