diff --git a/src/gui/processing/qgsprocessingalgorithmdialogbase.cpp b/src/gui/processing/qgsprocessingalgorithmdialogbase.cpp
index db66f7c0fac..9091ebc3023 100644
--- a/src/gui/processing/qgsprocessingalgorithmdialogbase.cpp
+++ b/src/gui/processing/qgsprocessingalgorithmdialogbase.cpp
@@ -417,6 +417,16 @@ QString QgsProcessingAlgorithmDialogBase::formatHelp( QgsProcessingAlgorithm *al
 
 void QgsProcessingAlgorithmDialogBase::processEvents()
 {
+  if ( mAlgorithmTask )
+  {
+    // no need to call this - the algorithm is running in a thread.
+    // in fact, calling it causes a crash on Windows when the algorithm
+    // is running in a background thread... unfortunately we need something
+    // like this for non-threadable algorithms, otherwise there's no chance
+    // for users to hit cancel or see progress updates...
+    return;
+  }
+
   // So that we get a chance of hitting the Abort button
 #ifdef Q_OS_LINUX
   // For some reason on Windows hasPendingEvents() always return true,