diff --git a/python/plugins/processing/algs/saga/SagaAlgorithm.py b/python/plugins/processing/algs/saga/SagaAlgorithm.py
index 7d2a258b5dc..b9b52e7ffe0 100644
--- a/python/plugins/processing/algs/saga/SagaAlgorithm.py
+++ b/python/plugins/processing/algs/saga/SagaAlgorithm.py
@@ -138,6 +138,7 @@ class SagaAlgorithm(GeoAlgorithm):
         self.exportedLayers = {}
 
         self.preProcessInputs()
+        extent = None
 
         # 1: Export rasters to sgrd and vectors to shp
         # Tables must be in dbf format. We check that.