diff --git a/capellambse_context_diagrams/collectors/generic.py b/capellambse_context_diagrams/collectors/generic.py
index 474a3709..41927d9e 100644
--- a/capellambse_context_diagrams/collectors/generic.py
+++ b/capellambse_context_diagrams/collectors/generic.py
@@ -22,21 +22,21 @@
 
 SourceAndTarget = tuple[common.GenericElement, common.GenericElement]
 
-PHYSICAL_CONNECTOR_ATTR_NAMES = {"physical_ports"}
+PHYSICAL_CONNECTOR_ATTR_NAMES = ("physical_ports",)
 """Attribute of PhysicalComponents for receiving connections."""
-CONNECTOR_ATTR_NAMES = {"ports", "inputs", "outputs"}
+CONNECTOR_ATTR_NAMES = ("ports", "inputs", "outputs")
 """Attribute of GenericElements for receiving connections."""
-DIAGRAM_TYPE_TO_CONNECTOR_NAMES: dict[DT, set[str]] = {
-    DT.OAB: set(),
-    DT.OAIB: set(),
-    DT.OCB: set(),
-    DT.MCB: set(),
+DIAGRAM_TYPE_TO_CONNECTOR_NAMES: dict[DT, tuple[str, ...]] = {
+    DT.OAB: (),
+    DT.OAIB: (),
+    DT.OCB: (),
+    DT.MCB: (),
     DT.SAB: CONNECTOR_ATTR_NAMES,
     DT.SDFB: CONNECTOR_ATTR_NAMES,
     DT.LAB: CONNECTOR_ATTR_NAMES,
     DT.LDFB: CONNECTOR_ATTR_NAMES,
-    DT.PAB: CONNECTOR_ATTR_NAMES | PHYSICAL_CONNECTOR_ATTR_NAMES,
-    DT.PDFB: CONNECTOR_ATTR_NAMES | PHYSICAL_CONNECTOR_ATTR_NAMES,
+    DT.PAB: CONNECTOR_ATTR_NAMES + PHYSICAL_CONNECTOR_ATTR_NAMES,
+    DT.PDFB: CONNECTOR_ATTR_NAMES + PHYSICAL_CONNECTOR_ATTR_NAMES,
 }
 """Supported diagram types mapping to the attribute name of connectors."""
 MARKER_SIZE = 3