diff --git a/ChangeLog b/ChangeLog
index 4fb7249fd..2bd6092ec 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2008-08-18	Tobias Doerffel	<tobydox/at/users/dot/sourceforge/dot/net>
+
+	* include/controller.h:
+	* src/core/controller.cpp:
+	* src/gui/automatable_model_view.cpp:
+	* src/gui/controller_connection_dialog.cpp:
+	Detect loops before allowing controller-connection
+
 2008-08-07	Tobias Doerffel	<tobydox/at/users/dot/sourceforge/dot/net>
 
 	* CMakeLists.txt:
diff --git a/include/controller.h b/include/controller.h
index d7d25fa7c..d022c88be 100644
--- a/include/controller.h
+++ b/include/controller.h
@@ -114,6 +114,8 @@ public slots:
 		m_name = _new_name;
 	}
 
+	bool hasModel( const model * m );
+
 
 protected:
 	// The internal per-controller get-value function
diff --git a/src/core/controller.cpp b/src/core/controller.cpp
index b0e14a6ad..a95765b37 100644
--- a/src/core/controller.cpp
+++ b/src/core/controller.cpp
@@ -190,6 +190,36 @@ controller * controller::create( const QDomElement & _this, model * _parent )
 
 
 
+bool controller::hasModel( const model * m )
+{
+	QObjectList chldren = children();
+	for( int i = 0; i < chldren.size(); ++i )
+	{
+		QObject * c = chldren.at(i);
+		automatableModel * am = qobject_cast<automatableModel*>(c);
+		if( am != NULL )
+		{
+			if( am == m )
+			{
+				return true;
+			}
+
+			controllerConnection * cc = am->getControllerConnection();
+			if( cc != NULL )
+			{
+				if( cc->getController()->hasModel( m ) )
+				{
+					return true;
+				}
+			}
+		}
+	}
+	
+	return false;
+}
+
+
+
 void controller::saveSettings( QDomDocument & _doc, QDomElement & _this )
 {
 	_this.setAttribute( "type", type() );
diff --git a/src/gui/automatable_model_view.cpp b/src/gui/automatable_model_view.cpp
index 4ab3dbc12..cf7d6a8c1 100644
--- a/src/gui/automatable_model_view.cpp
+++ b/src/gui/automatable_model_view.cpp
@@ -25,7 +25,6 @@
 
 #include <QtGui/QMenu>
 #include <QtGui/QMouseEvent>
-
 #include "automatable_model_view.h"
 #include "automation_pattern.h"
 #include "controller_connection_dialog.h"
@@ -183,32 +182,33 @@ void automatableModelViewSlots::execConnectionDialog( void )
 	controllerConnectionDialog * d = new controllerConnectionDialog( 
 			(QWidget*)engine::getMainWindow(), m );
 
-	d->exec();
-
-	// Actually chose something
-	if (d->chosenController() != NULL )
+	if( d->exec() == 1) 
 	{
-		// Update
-		if( m->getControllerConnection() )
+		// Actually chose something
+		if (d->chosenController() != NULL )
 		{
-			m->getControllerConnection()->
-				setController( d->chosenController() );
+			// Update
+			if( m->getControllerConnection() )
+			{
+				m->getControllerConnection()->
+					setController( d->chosenController() );
+			}
+			// New
+			else
+			{
+				controllerConnection * cc =
+						new controllerConnection( d->chosenController() );
+				m->setControllerConnection( cc );
+				//cc->setTargetName( m->displayName() );
+				
+			}
 		}
-		// New
+		// no controller, so delete existing connection
 		else
 		{
-			controllerConnection * cc =
-					new controllerConnection( d->chosenController() );
-			m->setControllerConnection( cc );
-			//cc->setTargetName( m->displayName() );
-			
+			removeConnection();
 		}
 	}
-	// no controller, so delete existing connection
-	else
-	{
-		removeConnection();
-	}
 
 	delete d;
 }
diff --git a/src/gui/controller_connection_dialog.cpp b/src/gui/controller_connection_dialog.cpp
index 1b8f16b95..19e6775cb 100644
--- a/src/gui/controller_connection_dialog.cpp
+++ b/src/gui/controller_connection_dialog.cpp
@@ -30,6 +30,7 @@
 #include <QtGui/QLineEdit>
 #include <QtGui/QPushButton>
 #include <QtGui/QScrollArea>
+#include <QMessageBox>
 
 #include "controller_connection_dialog.h"
 #include "controller_connection.h"
@@ -327,7 +328,15 @@ void controllerConnectionDialog::selectController( void )
 			m_controller = engine::getSong()->controllers().at( 
 					m_userController->model()->value() );
 		}
+
+		if( m_controller->hasModel( m_targetModel ) )
+		{
+			QMessageBox::warning(this, tr("LMMS"), tr("Cycle Detected."));
+			return;
+		}
+	
 	}
+
 	accept();
 }