diff --git a/plugins/PostProcessingPlugin/scripts/ChangeAtZ.py b/plugins/PostProcessingPlugin/scripts/ChangeAtZ.py
index 0ffd9e290b..b4036f7ff2 100644
--- a/plugins/PostProcessingPlugin/scripts/ChangeAtZ.py
+++ b/plugins/PostProcessingPlugin/scripts/ChangeAtZ.py
@@ -1305,7 +1305,7 @@ class ChangeAtZProcessor:
         self.targetLayer = None
         self.targetZ = None
         self.layerHeight = None
-        self.lastValues = {}
+        self.lastValues = {"speed": 100}
         self.linearRetraction = True
         self.insideTargetLayer = False
         self.targetValuesInjected = False