diff --git a/core/document.cpp b/core/document.cpp
index 2d5863408..c2a3b44d8 100644
--- a/core/document.cpp
+++ b/core/document.cpp
@@ -269,7 +269,7 @@ bool Document::openDocument( const QString & docFile, const KUrl& url, const KMi
 
     // 4. set initial page (restoring the page saved in xml if loaded)
     DocumentViewport loadedViewport = (*d->viewportIterator);
-    if ( loadedViewport.pageNumber != -1 )
+    if ( loadedViewport.isValid() )
     {
         (*d->viewportIterator) = DocumentViewport();
         if ( loadedViewport.pageNumber >= (int)pages_vector.size() )
@@ -295,7 +295,7 @@ bool Document::openDocument( const QString & docFile, const KUrl& url, const KMi
     }
     d->memCheckTimer->start( 2000 );
 
-    if (d->nextDocumentViewport.pageNumber != -1)
+    if (d->nextDocumentViewport.isValid())
     {
         setViewport(d->nextDocumentViewport);
         d->nextDocumentViewport = DocumentViewport();
@@ -865,7 +865,7 @@ void Document::setViewport( const DocumentViewport & viewport, int excludeId, bo
     //    kDebug() << "setViewport with the same viewport." << endl;
 
     // set internal viewport taking care of history
-    if ( oldViewport.pageNumber == viewport.pageNumber || oldViewport.pageNumber == -1 )
+    if ( oldViewport.pageNumber == viewport.pageNumber || !oldViewport.isValid() )
     {
         // if page is unchanged save the viewport at current position in queue
         oldViewport = viewport;
@@ -1279,7 +1279,7 @@ void Document::processLink( const Link * link )
             else
             {
                 // skip local links that point to nowhere (broken ones)
-                if (d->nextDocumentViewport.pageNumber == -1)
+                if (!d->nextDocumentViewport.isValid())
                     return;
 
                 setViewport( d->nextDocumentViewport, -1, true );
@@ -2054,6 +2054,11 @@ QString DocumentViewport::toString() const
     return s;
 }
 
+bool DocumentViewport::isValid() const
+{
+    return pageNumber != -1;
+}
+
 bool DocumentViewport::operator==( const DocumentViewport & vp ) const
 {
     bool equal = ( pageNumber == vp.pageNumber ) &&
diff --git a/core/document.h b/core/document.h
index 19fcbc80a..2c6ff1692 100644
--- a/core/document.h
+++ b/core/document.h
@@ -235,6 +235,7 @@ class OKULAR_EXPORT DocumentViewport
         DocumentViewport( int pageNumber = -1 );
         DocumentViewport( const QString & xmlDesc );
         QString toString() const;
+        bool isValid() const;
         bool operator==( const DocumentViewport & vp ) const;
 };
 
diff --git a/core/link.cpp b/core/link.cpp
index 1a8f0ca06..80a160f83 100644
--- a/core/link.cpp
+++ b/core/link.cpp
@@ -37,7 +37,7 @@ Link::LinkType LinkGoto::linkType() const
 
 QString LinkGoto::linkTip() const
 {
-    return m_extFileName.isEmpty() ? ( m_vp.pageNumber != -1 ? i18n( "Go to page %1", m_vp.pageNumber + 1 ) : "" ) :
+    return m_extFileName.isEmpty() ? ( m_vp.isValid() ? i18n( "Go to page %1", m_vp.pageNumber + 1 ) : "" ) :
                                      i18n("Open external file");
 }
 
diff --git a/generators/poppler/generator_pdf.cpp b/generators/poppler/generator_pdf.cpp
index 1b8e194ba..8fd8a56ae 100644
--- a/generators/poppler/generator_pdf.cpp
+++ b/generators/poppler/generator_pdf.cpp
@@ -74,7 +74,7 @@ static void fillViewportFromLinkDestination( Okular::DocumentViewport &viewport,
 {
     viewport.pageNumber = destination.pageNumber() - 1;
 
-    if (viewport.pageNumber == -1) return;
+    if (!viewport.isValid()) return;
 
     // get destination position
     // TODO add other attributes to the viewport (taken from link)
diff --git a/ui/toc.cpp b/ui/toc.cpp
index 417f87f81..2603a1549 100644
--- a/ui/toc.cpp
+++ b/ui/toc.cpp
@@ -57,7 +57,7 @@ class TOCItem : public QTreeWidgetItem
             }
 
             QString text = e.tagName();
-            if ( m_viewport.pageNumber != -1 )
+            if ( m_viewport.isValid() )
                 text.prepend( QString::number( m_viewport.pageNumber + 1 ) + PAGEITEMDELEGATE_SEPARATOR );
             setText( 0, text );
         }