diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 23f5f1369..5d060ea59 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -8,7 +8,7 @@ guava = "33.0.0-jre"
 stitch = "0.6.2"
 tiny-remapper = "0.10.4"
 access-widener = "2.1.0"
-mapping-io = "0.6.1"
+mapping-io = "0.7.0"
 lorenz-tiny = "4.0.2"
 mercury = "0.4.2"
 loom-native = "0.2.0"
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/tiny/MappingsMerger.java b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/tiny/MappingsMerger.java
index 5827a437d..2b83af30b 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/tiny/MappingsMerger.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/tiny/MappingsMerger.java
@@ -29,9 +29,7 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.util.Arrays;
 import java.util.Map;
-import java.util.regex.Pattern;
 
 import com.google.common.base.Stopwatch;
 import org.jetbrains.annotations.VisibleForTesting;
@@ -42,9 +40,9 @@
 import net.fabricmc.loom.configuration.providers.mappings.IntermediateMappingsService;
 import net.fabricmc.loom.configuration.providers.minecraft.MinecraftProvider;
 import net.fabricmc.mappingio.adapter.MappingSourceNsSwitch;
+import net.fabricmc.mappingio.adapter.OuterClassNamePropagator;
 import net.fabricmc.mappingio.format.tiny.Tiny2FileReader;
 import net.fabricmc.mappingio.format.tiny.Tiny2FileWriter;
-import net.fabricmc.mappingio.tree.MappingTree;
 import net.fabricmc.mappingio.tree.MemoryMappingTree;
 
 public final class MappingsMerger {
@@ -77,10 +75,9 @@ public static void mergeAndSaveMappings(Path from, Path out, IntermediateMapping
 		MappingSourceNsSwitch nsSwitch = new MappingSourceNsSwitch(nsCompleter, MappingsNamespace.OFFICIAL.toString());
 		intermediaryTree.accept(nsSwitch);
 
-		inheritMappedNamesOfEnclosingClasses(officialTree);
-
 		try (var writer = new Tiny2FileWriter(Files.newBufferedWriter(out, StandardCharsets.UTF_8), false)) {
-			officialTree.accept(writer);
+			var classNamePropagator = new OuterClassNamePropagator(writer);
+			officialTree.accept(classNamePropagator);
 		}
 	}
 
@@ -105,38 +102,4 @@ public static void legacyMergeAndSaveMappings(Path from, Path out, IntermediateM
 			officialTree.accept(writer);
 		}
 	}
-
-	/**
-	 * Searches the mapping tree for inner classes with no mapped name, whose enclosing classes have mapped names.
-	 * Currently, Yarn does not export mappings for these inner classes.
-	 */
-	private static void inheritMappedNamesOfEnclosingClasses(MemoryMappingTree tree) {
-		int intermediaryIdx = tree.getNamespaceId("intermediary");
-		int namedIdx = tree.getNamespaceId("named");
-
-		// The tree does not have an index by intermediary names by default
-		tree.setIndexByDstNames(true);
-
-		for (MappingTree.ClassMapping classEntry : tree.getClasses()) {
-			String intermediaryName = classEntry.getDstName(intermediaryIdx);
-			String namedName = classEntry.getDstName(namedIdx);
-
-			if (intermediaryName.equals(namedName) && intermediaryName.contains("$")) {
-				String[] path = intermediaryName.split(Pattern.quote("$"));
-				int parts = path.length;
-
-				for (int i = parts - 2; i >= 0; i--) {
-					String currentPath = String.join("$", Arrays.copyOfRange(path, 0, i + 1));
-					String namedParentClass = tree.mapClassName(currentPath, intermediaryIdx, namedIdx);
-
-					if (!namedParentClass.equals(currentPath)) {
-						classEntry.setDstName(namedParentClass
-										+ "$" + String.join("$", Arrays.copyOfRange(path, i + 1, path.length)),
-								namedIdx);
-						break;
-					}
-				}
-			}
-		}
-	}
 }