diff --git a/src/ifcopenshell-python/ifcopenshell/util/system.py b/src/ifcopenshell-python/ifcopenshell/util/system.py
index 833d85a941..832daefc0d 100644
--- a/src/ifcopenshell-python/ifcopenshell/util/system.py
+++ b/src/ifcopenshell-python/ifcopenshell/util/system.py
@@ -78,7 +78,7 @@ def get_element_systems(element: ifcopenshell.entity_instance) -> list[ifcopensh
 def get_element_zones(element: ifcopenshell.entity_instance) -> list[ifcopenshell.entity_instance]:
     results = []
     for rel in element.HasAssignments:
-        if rel.is_a("IfcRelAssignsToGroup"):
+        if not rel.is_a("IfcRelAssignsToGroup"):
             continue
         group = rel.RelatingGroup
         if not group.is_a("IfcZone"):