2 files changed, 7 insertions, 1 deletions

diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/GuiController.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/GuiController.java
index 6eab0f8..c579901 100644
--- a/enigma-swing/src/main/java/cuchaz/enigma/gui/GuiController.java
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/GuiController.java
@@ -29,6 +29,7 @@ import javax.swing.JOptionPane;
 import javax.swing.SwingUtilities;
 
 import com.google.common.collect.Lists;
+import org.jetbrains.annotations.ApiStatus;
 
 import cuchaz.enigma.Enigma;
 import cuchaz.enigma.EnigmaProfile;
@@ -139,6 +140,7 @@ public class GuiController implements ClientPacketHandler {
                 this.gui.onCloseJar();
         }
 
+        @ApiStatus.Internal
         public CompletableFuture<Void> openMappings(MappingFormat format, Path path, boolean useMappingIo) {
                 System.getProperties().setProperty("enigma.use_mappingio", useMappingIo ? "true" : "false");
                 return openMappings(format, path);
@@ -182,6 +184,7 @@ public class GuiController implements ClientPacketHandler {
                 return saveMappings(path, loadedMappingFormat);
         }
 
+        @ApiStatus.Internal
         public CompletableFuture<Void> saveMappings(Path path, MappingFormat format, boolean useMappingIo) {
                 System.getProperties().setProperty("enigma.use_mappingio", useMappingIo ? "true" : "false");
                 return saveMappings(path, format);
diff --git a/enigma/src/main/java/cuchaz/enigma/translation/mapping/serde/MappingFormat.java b/enigma/src/main/java/cuchaz/enigma/translation/mapping/serde/MappingFormat.java
index 530aff4..88f722c 100644
--- a/enigma/src/main/java/cuchaz/enigma/translation/mapping/serde/MappingFormat.java
+++ b/enigma/src/main/java/cuchaz/enigma/translation/mapping/serde/MappingFormat.java
@@ -49,6 +49,7 @@ public enum MappingFormat {
         private final MappingsReader reader;
         private final net.fabricmc.mappingio.format.MappingFormat mappingIoCounterpart;
         private final boolean hasMappingIoWriter;
+        private boolean lastUsedMappingIoWriter;
 
         MappingFormat(MappingsWriter writer, MappingsReader reader, net.fabricmc.mappingio.format.MappingFormat mappingIoCounterpart, boolean hasMappingIoWriter) {
                 this.writer = writer;
@@ -67,7 +68,8 @@ public enum MappingFormat {
                                 throw new IllegalStateException(name() + " does not support writing");
                         }
 
-                        writer.write(mappings, delta, path, progressListener, saveParameters);
+                        writer.write(mappings, lastUsedMappingIoWriter ? MappingDelta.added(mappings) : delta, path, progressListener, saveParameters);
+                        lastUsedMappingIoWriter = false;
                         return;
                 }
 
@@ -78,6 +80,7 @@ public enum MappingFormat {
 
                         tree.accept(MappingWriter.create(path, mappingIoCounterpart), VisitOrder.createByName());
                         progressListener.step(1, I18n.translate("progress.done"));
+                        lastUsedMappingIoWriter = true;
                 } catch (IOException e) {
                         throw new UncheckedIOException(e);
                 }