diff --git a/SabreTools.DatFiles/DatFile.Removal.cs b/SabreTools.DatFiles/DatFile.Removal.cs
index 568b7968..b501e146 100644
--- a/SabreTools.DatFiles/DatFile.Removal.cs
+++ b/SabreTools.DatFiles/DatFile.Removal.cs
@@ -151,9 +151,9 @@ namespace SabreTools.DatFiles
             // Get the combined list of fields to remove
             var fieldNames = new HashSet<string>();
             if (itemFieldNames.ContainsKey(itemType))
-                fieldNames.IntersectWith(itemFieldNames[itemType]);
+                fieldNames.UnionWith(itemFieldNames[itemType]);
             if (itemFieldNames.ContainsKey("item"))
-                fieldNames.IntersectWith(itemFieldNames["item"]);
+                fieldNames.UnionWith(itemFieldNames["item"]);
 
             // If the field specifically contains Name, set it separately
             if (fieldNames.Contains(Models.Metadata.Rom.NameKey))
diff --git a/SabreTools.DatFiles/ItemDictionary.cs b/SabreTools.DatFiles/ItemDictionary.cs
index 61c789bb..3e2244bf 100644
--- a/SabreTools.DatFiles/ItemDictionary.cs
+++ b/SabreTools.DatFiles/ItemDictionary.cs
@@ -1286,7 +1286,7 @@ namespace SabreTools.DatFiles
                         if (devItems == null)
                             continue;
 
-                        newDeviceReferences.IntersectWith(devItems
+                        newDeviceReferences.UnionWith(devItems
                             .Where(i => i is DeviceRef)
                             .Select(i => (i as DeviceRef)!.GetName()!));
 
@@ -1336,7 +1336,7 @@ namespace SabreTools.DatFiles
                         if (slotItems == null)
                             continue;
 
-                        newSlotOptions.IntersectWith(slotItems
+                        newSlotOptions.UnionWith(slotItems
                             .Where(i => i is Slot)
                             .Where(s => (s as Slot)!.SlotOptionsSpecified)
                             .SelectMany(s => (s as Slot)!.GetFieldValue<SlotOption[]?>(Models.Metadata.Slot.SlotOptionKey)!)
diff --git a/SabreTools.DatFiles/ItemDictionaryDB.cs b/SabreTools.DatFiles/ItemDictionaryDB.cs
index 91b2b8d6..6309d104 100644
--- a/SabreTools.DatFiles/ItemDictionaryDB.cs
+++ b/SabreTools.DatFiles/ItemDictionaryDB.cs
@@ -1716,7 +1716,7 @@ namespace SabreTools.DatFiles
                             continue;
 
                         // Add to the list of new device reference names
-                        newDeviceReferences.IntersectWith(devItems
+                        newDeviceReferences.UnionWith(devItems
                             .Where(i => i.Item2 is DeviceRef)
                             .Select(i => (i.Item2 as DeviceRef)!.GetName()!));
 
@@ -1771,7 +1771,7 @@ namespace SabreTools.DatFiles
                             continue;
 
                         // Add to the list of new slot option names
-                        newSlotOptions.IntersectWith(slotItems
+                        newSlotOptions.UnionWith(slotItems
                             .Where(i => i.Item2 is Slot)
                             .Where(s => (s.Item2 as Slot)!.SlotOptionsSpecified)
                             .SelectMany(s => (s.Item2 as Slot)!.GetFieldValue<SlotOption[]?>(Models.Metadata.Slot.SlotOptionKey)!)
diff --git a/SabreTools.DatTools/Replacer.cs b/SabreTools.DatTools/Replacer.cs
index b5561a8e..0f251ca2 100644
--- a/SabreTools.DatTools/Replacer.cs
+++ b/SabreTools.DatTools/Replacer.cs
@@ -64,9 +64,9 @@ namespace SabreTools.DatTools
             // Get the combined list of fields to remove
             var fieldNames = new HashSet<string>();
             if (itemFieldNames.ContainsKey(itemType))
-                fieldNames.IntersectWith(itemFieldNames[itemType]);
+                fieldNames.UnionWith(itemFieldNames[itemType]);
             if (itemFieldNames.ContainsKey("item"))
-                fieldNames.IntersectWith(itemFieldNames["item"]);
+                fieldNames.UnionWith(itemFieldNames["item"]);
 
             // If the field specifically contains Name, set it separately
             if (fieldNames.Contains(Models.Metadata.Rom.NameKey))