diff --git a/tabbox/clientmodel.cpp b/tabbox/clientmodel.cpp
index 3b0f1dbddc..063bc975e5 100644
--- a/tabbox/clientmodel.cpp
+++ b/tabbox/clientmodel.cpp
@@ -95,7 +95,7 @@ int ClientModel::columnCount( const QModelIndex& parent ) const
             count = 1;
             break;
         case TabBoxConfig::HorizontalVerticalLayout:
-            count = qRound( sqrt( m_clientList.count() ) );
+            count = qRound( sqrt(float( m_clientList.count() )) );
             if( count * count < m_clientList.count() )
                 count++;
             break;
@@ -116,7 +116,7 @@ int ClientModel::rowCount( const QModelIndex& parent ) const
             count = m_clientList.count();
             break;
         case TabBoxConfig::HorizontalVerticalLayout:
-            count = qRound( sqrt( m_clientList.count() ) );
+            count = qRound( sqrt( float( m_clientList.count() )) );
             break;
         }
     return qMax( count, 1 );
diff --git a/tabbox/desktopmodel.cpp b/tabbox/desktopmodel.cpp
index 07388c33a4..f5d2f29a42 100644
--- a/tabbox/desktopmodel.cpp
+++ b/tabbox/desktopmodel.cpp
@@ -75,7 +75,7 @@ int DesktopModel::columnCount( const QModelIndex& parent ) const
             count = 1;
             break;
         case TabBoxConfig::HorizontalVerticalLayout:
-            count = qRound( sqrt( m_desktopList.count() ) );
+            count = qRound( sqrt( float(m_desktopList.count() )) );
             if( count * count < m_desktopList.count() )
                 count++;
             // TODO: pager layout?
@@ -97,7 +97,7 @@ int DesktopModel::rowCount( const QModelIndex& parent ) const
             count = m_desktopList.count();
             break;
         case TabBoxConfig::HorizontalVerticalLayout:
-            count = qRound( sqrt( m_desktopList.count() ) );
+            count = qRound( sqrt( float(m_desktopList.count()) ) );
             // TODO: pager layout?
             break;
         }