diff --git a/src/core/qgstaskmanager.cpp b/src/core/qgstaskmanager.cpp
index 61d536513cd..7e1627676a9 100644
--- a/src/core/qgstaskmanager.cpp
+++ b/src/core/qgstaskmanager.cpp
@@ -29,6 +29,7 @@ QgsTask::QgsTask( const QString &name, Flags flags )
   : mFlags( flags )
   , mDescription( name )
 {
+  mNotStartedMutex.lock();
 }
 
 QgsTask::~QgsTask()
@@ -41,6 +42,7 @@ QgsTask::~QgsTask()
     delete subTask.task;
   }
   mNotFinishedMutex.unlock();
+  mNotStartedMutex.unlock();
 }
 
 void QgsTask::setDescription( const QString &description )
@@ -55,6 +57,7 @@ qint64 QgsTask::elapsedTime() const
 
 void QgsTask::start()
 {
+  mNotStartedMutex.unlock();
   mNotFinishedMutex.lock();
   mStartCount++;
   Q_ASSERT( mStartCount == 1 );
@@ -152,6 +155,9 @@ QList<QgsMapLayer *> QgsTask::dependentLayers() const
 
 bool QgsTask::waitForFinished( int timeout )
 {
+  // We wait the task to be started
+  mNotStartedMutex.lock();
+
   bool rv = true;
   if ( mOverallStatus == Complete || mOverallStatus == Terminated )
   {
diff --git a/src/core/qgstaskmanager.h b/src/core/qgstaskmanager.h
index 6e7a72674e1..e71bbe89fb0 100644
--- a/src/core/qgstaskmanager.h
+++ b/src/core/qgstaskmanager.h
@@ -310,6 +310,7 @@ class CORE_EXPORT QgsTask : public QObject
      * it's used as a trigger for waitForFinished.
      */
     QMutex mNotFinishedMutex;
+    QMutex mNotStartedMutex;
 
     //! Progress of this (parent) task alone
     double mProgress = 0.0;