diff --git a/cura/Settings/GlobalStack.py b/cura/Settings/GlobalStack.py
index ec3a2c05fd..0b46c53da1 100644
--- a/cura/Settings/GlobalStack.py
+++ b/cura/Settings/GlobalStack.py
@@ -113,7 +113,7 @@ class GlobalStack(ContainerStack):
 
     def addExtruder(self, extruder):
         extruder_count = self.getProperty("machine_extruder_count", "value")
-        if len(self._extruders) > extruder_count:
+        if len(self._extruders) + 1 > extruder_count:
             raise Exceptions.TooManyExtrudersError("Tried to add extruder to {id} but its extruder count is {count}".format(id = self.id, count = extruder_count))
 
         self._extruders.append(extruder)