diff --git a/packages/placeholder-plain/package.json b/packages/placeholder-plain/package.json
index 0524f62b..5c7cdbda 100644
--- a/packages/placeholder-plain/package.json
+++ b/packages/placeholder-plain/package.json
@@ -36,6 +36,7 @@
         "lint": "eslint -c .eslintrc --ignore-path ../../.eslintignore ./"
     },
     "dependencies": {
+        "@signpdf/internal-utils": "*",
         "@signpdf/placeholder-pdfkit010": "*",
         "@signpdf/utils": "*"
     },
@@ -49,6 +50,7 @@
         "@babel/node": "^7.0.0",
         "@babel/plugin-syntax-object-rest-spread": "^7.0.0",
         "@babel/preset-env": "^7.4.2",
+        "@signpdf/internal-utils": "*",
         "@types/node": ">=12.0.0",
         "@types/node-forge": "^1.2.1",
         "assertion-error": "^1.1.0",
diff --git a/packages/placeholder-plain/src/__snapshots__/createBufferTrailer.test.js.snap b/packages/placeholder-plain/src/__snapshots__/createBufferTrailer.test.js.snap
new file mode 100644
index 00000000..9024fddb
--- /dev/null
+++ b/packages/placeholder-plain/src/__snapshots__/createBufferTrailer.test.js.snap
@@ -0,0 +1,51 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`createBufferTrailer creates expected outputs 1`] = `
+"xref
+0 1
+0000000000 65535 f 
+trailer
+<<
+/Size 3
+/Root 1 0 R
+/Info 2 0 R
+/Prev 4220
+>>
+startxref
+4654
+%%EOF"
+`;
+
+exports[`createBufferTrailer creates expected outputs 2`] = `
+"xref
+0 1
+0000000000 65535 f 
+trailer
+<<
+/Size 3
+/Root 1 0 R
+/Prev 4220
+>>
+startxref
+4654
+%%EOF"
+`;
+
+exports[`createBufferTrailer creates expected outputs 3`] = `
+"xref
+0 1
+0000000000 65535 f 
+3 1
+0000004077 00000 n 
+4 1
+0000003812 00000 n 
+trailer
+<<
+/Size 3
+/Root 1 0 R
+/Prev 4220
+>>
+startxref
+4654
+%%EOF"
+`;
diff --git a/packages/placeholder-plain/src/createBufferTrailer.test.js b/packages/placeholder-plain/src/createBufferTrailer.test.js
new file mode 100644
index 00000000..52c8d3c7
--- /dev/null
+++ b/packages/placeholder-plain/src/createBufferTrailer.test.js
@@ -0,0 +1,36 @@
+import {readTestResource} from '@signpdf/internal-utils';
+import createBufferTrailer from './createBufferTrailer';
+
+describe(createBufferTrailer, () => {
+    it('creates expected outputs', () => {
+        const pdfBuffer = readTestResource('signed.pdf');
+
+        /** @type {import("./readPdf").ReadPdfReturnType} */
+        const info = {
+            xref: {
+                startingIndex: 0,
+                maxIndex: 2,
+                offsets: new Map([
+                    [1, 4163],
+                    [2, 4098],
+                ]),
+            },
+            rootRef: '1 0 R',
+            root: '\n/Type /Catalog\n/Pages 1 0 R\n/AcroForm 9 0 R\n',
+            infoRef: '2 0 R',
+            trailerStart: 4510,
+            previousXrefs: [],
+            xRefPosition: 4220,
+        };
+        const addedReferences = new Map();
+
+        expect(createBufferTrailer(pdfBuffer, info, addedReferences).toString()).toMatchSnapshot();
+
+        info.infoRef = undefined;
+        expect(createBufferTrailer(pdfBuffer, info, addedReferences).toString()).toMatchSnapshot();
+
+        addedReferences.set(3, 4077);
+        addedReferences.set(4, 3812);
+        expect(createBufferTrailer(pdfBuffer, info, addedReferences).toString()).toMatchSnapshot();
+    });
+});