i18n

app/core/src/main/java/stirling/software/SPDF/controller/api/MergeController.java

@@ -185,40 +185,39 @@ public class MergeController {
         return new String[0];
     }
 
-    // Adds a table of contents to the merged document using filenames as chapter titles
-    private void addTableOfContents(PDDocument mergedDocument, MultipartFile[] files) {
-        // Create the document outline
+    // Reads page counts from on-disk source files in read-only mode. A failed read falls back to
+    // 1 so TOC generation still produces a usable (if slightly misaligned) outline.
+    private int[] collectPageCounts(File[] sourceFiles) {
+        int[] counts = new int[sourceFiles.length];
+        for (int i = 0; i < sourceFiles.length; i++) {
+            try (PDDocument doc = pdfDocumentFactory.load(sourceFiles[i], true)) {
+                counts[i] = doc.getNumberOfPages();
+            } catch (IOException e) {
+                ExceptionUtils.logException("page count for TOC", e);
+                counts[i] = 1;
+            }
+        }
+        return counts;
+    }
+
+    // Adds a table of contents to the merged document using filenames as chapter titles.
+    // Page counts are passed in so we don't re-open every source PDF just to count pages.
+    private void addTableOfContents(
+            PDDocument mergedDocument, MultipartFile[] files, int[] pageCounts) {
         PDDocumentOutline outline = new PDDocumentOutline();
         mergedDocument.getDocumentCatalog().setDocumentOutline(outline);
 
-        int pageIndex = 0; // Current page index in the merged document
-
-        // Iterate through the original files
-        for (MultipartFile file : files) {
-            // Get the filename without extension to use as bookmark title
-            String filename = file.getOriginalFilename();
-            String title = GeneralUtils.removeExtension(filename);
-
-            // Create an outline item for this file
+        int pageIndex = 0;
+        for (int i = 0; i < files.length; i++) {
+            String title = GeneralUtils.removeExtension(files[i].getOriginalFilename());
             PDOutlineItem item = new PDOutlineItem();
             item.setTitle(title);
-
-            // Set the destination to the first page of this file in the merged document
             if (pageIndex < mergedDocument.getNumberOfPages()) {
-                PDPage page = mergedDocument.getPage(pageIndex);
-                item.setDestination(page);
+                item.setDestination(mergedDocument.getPage(pageIndex));
             }
-
-            // Add the item to the outline
             outline.addLast(item);
-
-            // Increment page index for the next file
-            try (PDDocument doc = pdfDocumentFactory.load(file)) {
-                pageIndex += doc.getNumberOfPages();
-            } catch (IOException e) {
-                ExceptionUtils.logException("document loading for TOC generation", e);
-                pageIndex++; // Increment by at least one if we can't determine page count
-            }
+            int count = pageCounts[i];
+            pageIndex += count > 0 ? count : 1;
         }
     }
 
@@ -288,6 +287,7 @@ public class MergeController {
 
         boolean removeCertSign = Boolean.TRUE.equals(request.getRemoveCertSign());
         boolean generateToc = request.isGenerateToc();
+        boolean preserveAccessibility = request.isPreserveAccessibility();
 
         MultipartFile[] files = request.getFileInput();
         if (files == null) {
@@ -306,31 +306,34 @@ public class MergeController {
                             request.getSortType())); // Sort files based on requested sort type
         }
 
-        try (TempFile mt = new TempFile(tempFileManager, ".pdf")) {
-
+        // Hold the merge output until response streaming completes. We only close it on failure;
+        // on success ownership transfers to the response (deleted when Spring closes the stream).
+        TempFile mergeOutput = new TempFile(tempFileManager, ".pdf");
+        boolean keepMergeOutput = false;
+        try {
             PDFMergerUtility mergerUtility = new PDFMergerUtility();
+            // OPTIMIZE_RESOURCES_MODE closes source documents progressively and skips
+            // structure-tree copying — drops PDF/UA tags but uses much less heap.
+            // PDFBOX_LEGACY_MODE preserves tags at the cost of higher peak heap.
+            mergerUtility.setDocumentMergeMode(
+                    preserveAccessibility
+                            ? PDFMergerUtility.DocumentMergeMode.PDFBOX_LEGACY_MODE
+                            : PDFMergerUtility.DocumentMergeMode.OPTIMIZE_RESOURCES_MODE);
             long totalSize = 0;
-            List<Integer> invalidIndexes = new ArrayList<>();
+            File[] sourceFiles = new File[files.length];
             for (int index = 0; index < files.length; index++) {
                 MultipartFile multipartFile = files[index];
                 totalSize += multipartFile.getSize();
-                File tempFile =
-                        tempFileManager.convertMultipartFileToFile(
-                                multipartFile); // Convert MultipartFile to File
-                filesToDelete.add(tempFile); // Add temp file to the list for later deletion
-
-                // Pre-validate each PDF so we can report which one(s) are broken
-                // Use the original MultipartFile to avoid deleting the tempFile during validation
-                try (PDDocument ignored = pdfDocumentFactory.load(multipartFile)) {
-                    // OK
-                } catch (IOException e) {
-                    ExceptionUtils.logException("PDF pre-validate", e);
-                    invalidIndexes.add(index);
-                }
-                mergerUtility.addSource(tempFile); // Add source file to the merger utility
+                File tempFile = tempFileManager.convertMultipartFileToFile(multipartFile);
+                filesToDelete.add(tempFile);
+                sourceFiles[index] = tempFile;
+                mergerUtility.addSource(tempFile);
             }
+            // Pre-validation is intentionally omitted: PDFMergerUtility surfaces corrupted inputs
+            // via PdfErrorUtils.isCorruptedPdfError below, and a separate validation pass would
+            // double-allocate PDDocument graphs and re-spool every source >10 MB to disk.
 
-            mergerUtility.setDestinationFileName(mt.getFile().getAbsolutePath());
+            mergerUtility.setDestinationFileName(mergeOutput.getFile().getAbsolutePath());
 
             try {
                 mergerUtility.mergeDocuments(
@@ -339,39 +342,59 @@ public class MergeController {
             } catch (IOException e) {
                 ExceptionUtils.logException("PDF merge", e);
                 if (PdfErrorUtils.isCorruptedPdfError(e)) {
+                    // Identify which source file(s) are corrupt for operator diagnostics.
+                    // Only runs on the failure path so the happy path stays fast.
+                    List<String> badFiles = new ArrayList<>();
+                    for (int i = 0; i < sourceFiles.length; i++) {
+                        try (PDDocument ignored =
+                                pdfDocumentFactory.load(sourceFiles[i], true)) {
+                            // OK
+                        } catch (IOException corruptInput) {
+                            String name = files[i].getOriginalFilename();
+                            badFiles.add(name != null ? name : ("index " + i));
+                        }
+                    }
+                    if (!badFiles.isEmpty()) {
+                        log.warn("Corrupted PDFs in merge input: {}", badFiles);
+                    }
                     throw ExceptionUtils.createMultiplePdfCorruptedException(e);
                 }
                 throw e;
             }
 
-            // Load the merged PDF document and operate on it inside try-with-resources
-            try (PDDocument mergedDocument = pdfDocumentFactory.load(mt.getFile())) {
-                // Remove signatures if removeCertSign is true
-                if (removeCertSign) {
-                    PDDocumentCatalog catalog = mergedDocument.getDocumentCatalog();
-                    PDAcroForm acroForm = catalog.getAcroForm();
-                    if (acroForm != null) {
-                        List<PDField> fieldsToRemove =
-                                acroForm.getFields().stream()
-                                        .filter(PDSignatureField.class::isInstance)
-                                        .toList();
+            // Common case: caller wants neither cert-sign removal nor a TOC. Skip the
+            // load-and-resave round-trip entirely — the merged file on disk is the response.
+            // For 4000+ page jobs this avoids materialising the merged PDDocument in heap.
+            if (!removeCertSign && !generateToc) {
+                outputTempFile = mergeOutput;
+                keepMergeOutput = true;
+            } else {
+                // Page counts are needed only when generating a TOC. Read them from the already-
+                // on-disk source files in read-only mode (no metadata mutation, no extra spool).
+                int[] pageCounts = generateToc ? collectPageCounts(sourceFiles) : null;
 
-                        if (!fieldsToRemove.isEmpty()) {
-                            acroForm.flatten(
-                                    fieldsToRemove,
-                                    false); // Flatten the fields, effectively removing them
+                outputTempFile = new TempFile(tempFileManager, ".pdf");
+                try (PDDocument mergedDocument = pdfDocumentFactory.load(mergeOutput.getFile())) {
+                    // Resource cache off for the modify pass — we never call getImage() here,
+                    // and disabling it prevents PDFBox from caching XObjects when the page tree
+                    // is iterated during outline insertion or AcroForm flattening.
+                    mergedDocument.setResourceCache(null);
+                    if (removeCertSign) {
+                        PDDocumentCatalog catalog = mergedDocument.getDocumentCatalog();
+                        PDAcroForm acroForm = catalog.getAcroForm();
+                        if (acroForm != null) {
+                            List<PDField> fieldsToRemove =
+                                    acroForm.getFields().stream()
+                                            .filter(PDSignatureField.class::isInstance)
+                                            .toList();
+                            if (!fieldsToRemove.isEmpty()) {
+                                acroForm.flatten(fieldsToRemove, false);
+                            }
                         }
                     }
-                }
-
-                // Add table of contents if generateToc is true
-                if (generateToc && files.length > 0) {
-                    addTableOfContents(mergedDocument, files);
-                }
-
-                // Save the modified document to a temporary file
-                outputTempFile = new TempFile(tempFileManager, ".pdf");
-                try {
+                    if (generateToc && files.length > 0) {
+                        addTableOfContents(mergedDocument, files, pageCounts);
+                    }
                     mergedDocument.save(outputTempFile.getFile());
                 } catch (Exception e) {
                     outputTempFile.close();
@@ -380,7 +403,7 @@ public class MergeController {
                 }
             }
         } catch (Exception ex) {
-            if (outputTempFile != null) {
+            if (outputTempFile != null && outputTempFile != mergeOutput) {
                 outputTempFile.close();
             }
             if (ex instanceof IOException && PdfErrorUtils.isCorruptedPdfError((IOException) ex)) {
@@ -390,6 +413,9 @@ public class MergeController {
             }
             throw ex;
         } finally {
+            if (!keepMergeOutput && outputTempFile != mergeOutput) {
+                mergeOutput.close();
+            }
             for (File file : filesToDelete) {
                 tempFileManager.deleteTempFile(file); // Delete temporary files
             }

app/core/src/main/java/stirling/software/SPDF/model/api/general/MergePdfsRequest.java

@@ -40,6 +40,16 @@ public class MergePdfsRequest extends MultiplePDFFiles {
             defaultValue = "false")
     private boolean generateToc = false;
 
+    @Schema(
+            description =
+                    "Flag indicating whether to preserve PDF/UA accessibility tags (structure"
+                            + " tree) in the merged output. When false (default) the merger runs in"
+                            + " resource-optimised mode which drops tags but uses significantly less"
+                            + " heap. Set true when merging tagged PDFs intended for screen readers.",
+            requiredMode = Schema.RequiredMode.NOT_REQUIRED,
+            defaultValue = "false")
+    private boolean preserveAccessibility = false;
+
     @Schema(
             description =
                     "JSON array of client-provided IDs for each uploaded file (same order as fileInput)",

app/core/src/test/java/stirling/software/SPDF/controller/api/MergeControllerTest.java

@@ -75,137 +75,57 @@ class MergeControllerTest {
     void testAddTableOfContents_WithMultipleFiles_Success() throws Exception {
         // Given
         MultipartFile[] files = {mockFile1, mockFile2, mockFile3};
+        int[] pageCounts = {2, 2, 2};
 
-        // Mock the merged document setup
         when(mockMergedDocument.getDocumentCatalog()).thenReturn(mockCatalog);
         when(mockMergedDocument.getNumberOfPages()).thenReturn(6);
         when(mockMergedDocument.getPage(0)).thenReturn(mockPage1);
         when(mockMergedDocument.getPage(2)).thenReturn(mockPage2);
         when(mockMergedDocument.getPage(4)).thenReturn(mockPage1);
 
-        // Mock individual document loading for page count
-        PDDocument doc1 = mock(PDDocument.class);
-        PDDocument doc2 = mock(PDDocument.class);
-        PDDocument doc3 = mock(PDDocument.class);
-
-        when(pdfDocumentFactory.load(mockFile1)).thenReturn(doc1);
-        when(pdfDocumentFactory.load(mockFile2)).thenReturn(doc2);
-        when(pdfDocumentFactory.load(mockFile3)).thenReturn(doc3);
-
-        when(doc1.getNumberOfPages()).thenReturn(2);
-        when(doc2.getNumberOfPages()).thenReturn(2);
-        when(doc3.getNumberOfPages()).thenReturn(2);
-
         // When
-        Method addTableOfContentsMethod =
-                MergeController.class.getDeclaredMethod(
-                        "addTableOfContents", PDDocument.class, MultipartFile[].class);
-        addTableOfContentsMethod.setAccessible(true);
-        addTableOfContentsMethod.invoke(mergeController, mockMergedDocument, files);
+        invokeAddToc(mockMergedDocument, files, pageCounts);
 
         // Then
         ArgumentCaptor<PDDocumentOutline> outlineCaptor =
                 ArgumentCaptor.forClass(PDDocumentOutline.class);
         verify(mockCatalog).setDocumentOutline(outlineCaptor.capture());
+        assertNotNull(outlineCaptor.getValue());
 
-        PDDocumentOutline capturedOutline = outlineCaptor.getValue();
-        assertNotNull(capturedOutline);
-
-        // Verify that documents were loaded for page count
-        verify(pdfDocumentFactory).load(mockFile1);
-        verify(pdfDocumentFactory).load(mockFile2);
-        verify(pdfDocumentFactory).load(mockFile3);
-
-        // Verify document closing
-        verify(doc1).close();
-        verify(doc2).close();
-        verify(doc3).close();
+        // TOC must NOT re-open source PDFs to count pages — that was the OOM hot spot.
+        verifyNoInteractions(pdfDocumentFactory);
     }
 
     @Test
     void testAddTableOfContents_WithSingleFile_Success() throws Exception {
-        // Given
         MultipartFile[] files = {mockFile1};
+        int[] pageCounts = {3};
 
         when(mockMergedDocument.getDocumentCatalog()).thenReturn(mockCatalog);
         when(mockMergedDocument.getNumberOfPages()).thenReturn(3);
         when(mockMergedDocument.getPage(0)).thenReturn(mockPage1);
 
-        PDDocument doc1 = mock(PDDocument.class);
-        when(pdfDocumentFactory.load(mockFile1)).thenReturn(doc1);
-        when(doc1.getNumberOfPages()).thenReturn(3);
+        invokeAddToc(mockMergedDocument, files, pageCounts);
 
-        // When
-        Method addTableOfContentsMethod =
-                MergeController.class.getDeclaredMethod(
-                        "addTableOfContents", PDDocument.class, MultipartFile[].class);
-        addTableOfContentsMethod.setAccessible(true);
-        addTableOfContentsMethod.invoke(mergeController, mockMergedDocument, files);
-
-        // Then
         verify(mockCatalog).setDocumentOutline(any(PDDocumentOutline.class));
-        verify(pdfDocumentFactory).load(mockFile1);
-        verify(doc1).close();
+        verifyNoInteractions(pdfDocumentFactory);
     }
 
     @Test
     void testAddTableOfContents_WithEmptyArray_Success() throws Exception {
-        // Given
         MultipartFile[] files = {};
+        int[] pageCounts = {};
         when(mockMergedDocument.getDocumentCatalog()).thenReturn(mockCatalog);
 
-        // When
-        Method addTableOfContentsMethod =
-                MergeController.class.getDeclaredMethod(
-                        "addTableOfContents", PDDocument.class, MultipartFile[].class);
-        addTableOfContentsMethod.setAccessible(true);
-        addTableOfContentsMethod.invoke(mergeController, mockMergedDocument, files);
+        invokeAddToc(mockMergedDocument, files, pageCounts);
 
-        // Then
         verify(mockMergedDocument).getDocumentCatalog();
         verify(mockCatalog).setDocumentOutline(any(PDDocumentOutline.class));
         verifyNoInteractions(pdfDocumentFactory);
     }
 
-    @Test
-    void testAddTableOfContents_WithIOException_HandlesGracefully() throws Exception {
-        // Given
-        MultipartFile[] files = {mockFile1, mockFile2};
-
-        when(mockMergedDocument.getDocumentCatalog()).thenReturn(mockCatalog);
-        when(mockMergedDocument.getNumberOfPages()).thenReturn(4);
-        when(mockMergedDocument.getPage(anyInt()))
-                .thenReturn(mockPage1); // Use anyInt() to avoid stubbing conflicts
-
-        // First document loads successfully
-        PDDocument doc1 = mock(PDDocument.class);
-        when(pdfDocumentFactory.load(mockFile1)).thenReturn(doc1);
-        when(doc1.getNumberOfPages()).thenReturn(2);
-
-        // Second document throws IOException
-        when(pdfDocumentFactory.load(mockFile2))
-                .thenThrow(new IOException("Failed to load document"));
-
-        // When
-        Method addTableOfContentsMethod =
-                MergeController.class.getDeclaredMethod(
-                        "addTableOfContents", PDDocument.class, MultipartFile[].class);
-        addTableOfContentsMethod.setAccessible(true);
-
-        // Should not throw exception
-        assertDoesNotThrow(
-                () -> addTableOfContentsMethod.invoke(mergeController, mockMergedDocument, files));
-
-        // Then
-        verify(mockCatalog).setDocumentOutline(any(PDDocumentOutline.class));
-        verify(pdfDocumentFactory).load(mockFile1);
-        verify(pdfDocumentFactory).load(mockFile2);
-        verify(doc1).close();
-    }
-
     @Test
     void testAddTableOfContents_FilenameWithoutExtension_UsesFullName() throws Exception {
-        // Given
         MockMultipartFile fileWithoutExtension =
                 new MockMultipartFile(
                         "file",
@@ -213,53 +133,40 @@ class MergeControllerTest {
                         MediaType.APPLICATION_PDF_VALUE,
                         "PDF content".getBytes());
         MultipartFile[] files = {fileWithoutExtension};
+        int[] pageCounts = {1};
 
         when(mockMergedDocument.getDocumentCatalog()).thenReturn(mockCatalog);
         when(mockMergedDocument.getNumberOfPages()).thenReturn(1);
         when(mockMergedDocument.getPage(0)).thenReturn(mockPage1);
 
-        PDDocument doc = mock(PDDocument.class);
-        when(pdfDocumentFactory.load(fileWithoutExtension)).thenReturn(doc);
-        when(doc.getNumberOfPages()).thenReturn(1);
+        invokeAddToc(mockMergedDocument, files, pageCounts);
 
-        // When
-        Method addTableOfContentsMethod =
-                MergeController.class.getDeclaredMethod(
-                        "addTableOfContents", PDDocument.class, MultipartFile[].class);
-        addTableOfContentsMethod.setAccessible(true);
-        addTableOfContentsMethod.invoke(mergeController, mockMergedDocument, files);
-
-        // Then
         verify(mockCatalog).setDocumentOutline(any(PDDocumentOutline.class));
-        verify(doc).close();
+        verifyNoInteractions(pdfDocumentFactory);
     }
 
     @Test
     void testAddTableOfContents_PageIndexExceedsDocumentPages_HandlesGracefully() throws Exception {
-        // Given
         MultipartFile[] files = {mockFile1};
+        int[] pageCounts = {3};
 
         when(mockMergedDocument.getDocumentCatalog()).thenReturn(mockCatalog);
         when(mockMergedDocument.getNumberOfPages()).thenReturn(0); // No pages in merged document
 
-        PDDocument doc1 = mock(PDDocument.class);
-        when(pdfDocumentFactory.load(mockFile1)).thenReturn(doc1);
-        when(doc1.getNumberOfPages()).thenReturn(3);
+        assertDoesNotThrow(() -> invokeAddToc(mockMergedDocument, files, pageCounts));
 
-        // When
-        Method addTableOfContentsMethod =
-                MergeController.class.getDeclaredMethod(
-                        "addTableOfContents", PDDocument.class, MultipartFile[].class);
-        addTableOfContentsMethod.setAccessible(true);
-
-        // Should not throw exception
-        assertDoesNotThrow(
-                () -> addTableOfContentsMethod.invoke(mergeController, mockMergedDocument, files));
-
-        // Then
         verify(mockCatalog).setDocumentOutline(any(PDDocumentOutline.class));
         verify(mockMergedDocument, never()).getPage(anyInt());
-        verify(doc1).close();
+        verifyNoInteractions(pdfDocumentFactory);
+    }
+
+    private void invokeAddToc(PDDocument merged, MultipartFile[] files, int[] pageCounts)
+            throws Exception {
+        Method m =
+                MergeController.class.getDeclaredMethod(
+                        "addTableOfContents", PDDocument.class, MultipartFile[].class, int[].class);
+        m.setAccessible(true);
+        m.invoke(mergeController, merged, files, pageCounts);
     }
 
     @Test

frontend/public/locales/en-GB/translation.toml

@@ -4600,6 +4600,13 @@ label = "Generate table of contents in the merged file?"
 description = "Automatically creates a clickable table of contents in the merged PDF based on the original file names and page numbers."
 title = "Generate Table of Contents"
 
+[merge.preserveAccessibility]
+label = "Preserve accessibility tags? (uses more memory on large merges)"
+
+[merge.preserveAccessibility.tooltip]
+description = "Keeps PDF/UA structure tags (used by screen readers) in the merged output. Increases peak memory usage; leave off for large merges if accessibility is not required."
+title = "Preserve Accessibility Tags"
+
 [merge.removeDigitalSignature]
 label = "Remove digital signature in the merged file?"
 

frontend/src/core/components/tools/merge/MergeSettings.test.tsx

@@ -19,6 +19,7 @@ describe("MergeSettings", () => {
   const defaultParameters: MergeParameters = {
     removeDigitalSignature: false,
     generateTableOfContents: false,
+    preserveAccessibility: false,
   };
 
   const mockOnParameterChange = vi.fn();
@@ -86,6 +87,13 @@ describe("MergeSettings", () => {
       "generateTableOfContents",
       true,
     );
+
+    // Click the third checkbox (preserveAccessibility - should toggle from false to true)
+    fireEvent.click(checkboxes[2]);
+    expect(mockOnParameterChange).toHaveBeenCalledWith(
+      "preserveAccessibility",
+      true,
+    );
   });
 
   test("should call translation function with correct keys", () => {
@@ -107,5 +115,9 @@ describe("MergeSettings", () => {
       "merge.generateTableOfContents.label",
       "Generate table of contents in the merged file?",
     );
+    expect(mockT).toHaveBeenCalledWith(
+      "merge.preserveAccessibility.label",
+      "Preserve accessibility tags? (uses more memory on large merges)",
+    );
   });
 });

frontend/src/core/components/tools/merge/MergeSettings.tsx

@@ -50,6 +50,21 @@ const MergeSettings: React.FC<MergeSettingsProps> = ({
         }
         disabled={disabled}
       />
+
+      <Checkbox
+        label={t(
+          "merge.preserveAccessibility.label",
+          "Preserve accessibility tags? (uses more memory on large merges)",
+        )}
+        checked={parameters.preserveAccessibility}
+        onChange={(event) =>
+          onParameterChange(
+            "preserveAccessibility",
+            event.currentTarget.checked,
+          )
+        }
+        disabled={disabled}
+      />
     </Stack>
   );
 };

frontend/src/core/components/tooltips/useMergeTips.tsx

@@ -29,6 +29,16 @@ export const useMergeTips = (): TooltipContent => {
           "Automatically creates a clickable table of contents in the merged PDF based on the original file names and page numbers.",
         ),
       },
+      {
+        title: t(
+          "merge.preserveAccessibility.tooltip.title",
+          "Preserve Accessibility Tags",
+        ),
+        description: t(
+          "merge.preserveAccessibility.tooltip.description",
+          "Keeps PDF/UA structure tags (used by screen readers) in the merged output. Increases peak memory usage; leave off for large merges if accessibility is not required.",
+        ),
+      },
     ],
   };
 };

frontend/src/core/hooks/tools/merge/useMergeOperation.ts

@@ -33,6 +33,10 @@ const buildFormData = (
     "generateToc",
     (parameters.generateTableOfContents ?? false).toString(),
   );
+  formData.append(
+    "preserveAccessibility",
+    (parameters.preserveAccessibility ?? false).toString(),
+  );
 
   return formData;
 };

frontend/src/core/hooks/tools/merge/useMergeParameters.ts

@@ -7,11 +7,13 @@ import {
 export interface MergeParameters extends BaseParameters {
   removeDigitalSignature: boolean;
   generateTableOfContents: boolean;
+  preserveAccessibility: boolean;
 }
 
 export const defaultParameters: MergeParameters = {
   removeDigitalSignature: false,
   generateTableOfContents: false,
+  preserveAccessibility: false,
 };
 
 export type MergeParametersHook = BaseParametersHook<MergeParameters>;