diff --git a/packages/core/schematics/migrations/self-closing-tags-migration/self-closing-tags-migration.ts b/packages/core/schematics/migrations/self-closing-tags-migration/self-closing-tags-migration.ts
index e3ffe0f5e10..0c8ba375a42 100644
--- a/packages/core/schematics/migrations/self-closing-tags-migration/self-closing-tags-migration.ts
+++ b/packages/core/schematics/migrations/self-closing-tags-migration/self-closing-tags-migration.ts
@@ -110,12 +110,9 @@ export class SelfClosingTagsMigration extends TsurgeFunnelMigration<
     unitA: SelfClosingTagsCompilationUnitData,
     unitB: SelfClosingTagsCompilationUnitData,
   ): Promise<Serializable<SelfClosingTagsCompilationUnitData>> {
-    const uniqueReplacements = removeDuplicateReplacements([
-      ...unitA.tagReplacements,
-      ...unitB.tagReplacements,
-    ]);
-
-    return confirmAsSerializable({tagReplacements: uniqueReplacements});
+    return confirmAsSerializable({
+      tagReplacements: [...unitA.tagReplacements, ...unitB.tagReplacements],
+    });
   }
 
   override async globalMeta(
@@ -165,20 +162,3 @@ function prepareTextReplacement(
     }),
   );
 }
-
-function removeDuplicateReplacements(
-  replacements: SelfClosingTagsMigrationData[],
-): SelfClosingTagsMigrationData[] {
-  const uniqueFiles = new Set<string>();
-  const result: SelfClosingTagsMigrationData[] = [];
-
-  for (const replacement of replacements) {
-    const fileId = replacement.file.id;
-    if (!uniqueFiles.has(fileId)) {
-      uniqueFiles.add(fileId);
-      result.push(replacement);
-    }
-  }
-
-  return result;
-}
diff --git a/packages/core/schematics/ng-generate/cleanup-unused-imports/unused_imports_migration.ts b/packages/core/schematics/ng-generate/cleanup-unused-imports/unused_imports_migration.ts
index 36429f80b30..b08708338a9 100644
--- a/packages/core/schematics/ng-generate/cleanup-unused-imports/unused_imports_migration.ts
+++ b/packages/core/schematics/ng-generate/cleanup-unused-imports/unused_imports_migration.ts
@@ -94,6 +94,11 @@ export class UnusedImportsMigration extends TsurgeFunnelMigration<
         diag.length !== undefined &&
         diag.code === ngErrorCode(ErrorCode.UNUSED_STANDALONE_IMPORTS)
       ) {
+        // Skip files that aren't owned by this compilation unit.
+        if (!info.sourceFiles.includes(diag.file)) {
+          return;
+        }
+
         if (!nodePositions.has(diag.file)) {
           nodePositions.set(diag.file, new Set());
         }