diff --git a/x-pack/plugins/lists/server/services/items/buffer_lines.test.ts b/x-pack/plugins/lists/server/services/items/buffer_lines.test.ts
index 509233d006b73..7faef72c38907 100644
--- a/x-pack/plugins/lists/server/services/items/buffer_lines.test.ts
+++ b/x-pack/plugins/lists/server/services/items/buffer_lines.test.ts
@@ -23,9 +23,15 @@ describe('buffer_lines', () => {
     }).toThrow('bufferSize must be greater than zero');
   });
 
-  test('it can read a single line', (done) => {
+  test('two identical lines are collapsed into just one line without duplicates', (done) => {
     const input = new TestReadable();
+    input.push('--boundary\n');
+    input.push('Content-type: text/plain\n');
+    input.push('Content-Disposition: form-data; name="fieldName"; filename="filename.text"\n');
+    input.push('\n');
+    input.push('line one\n');
     input.push('line one\n');
+    input.push('--boundary--\n');
     input.push(null);
     const bufferedLine = new BufferLines({ bufferSize: IMPORT_BUFFER_SIZE, input });
     let linesToTest: string[] = [];
@@ -38,25 +44,8 @@ describe('buffer_lines', () => {
     });
   });
 
-  test('it can read a single line using a buffer size of 1', (done) => {
+  test('it can close out without writing any lines', (done) => {
     const input = new TestReadable();
-    input.push('line one\n');
-    input.push(null);
-    const bufferedLine = new BufferLines({ bufferSize: 1, input });
-    let linesToTest: string[] = [];
-    bufferedLine.on('lines', (lines: string[]) => {
-      linesToTest = [...linesToTest, ...lines];
-    });
-    bufferedLine.on('close', () => {
-      expect(linesToTest).toEqual(['line one']);
-      done();
-    });
-  });
-
-  test('it can read two lines', (done) => {
-    const input = new TestReadable();
-    input.push('line one\n');
-    input.push('line two\n');
     input.push(null);
     const bufferedLine = new BufferLines({ bufferSize: IMPORT_BUFFER_SIZE, input });
     let linesToTest: string[] = [];
@@ -64,74 +53,56 @@ describe('buffer_lines', () => {
       linesToTest = [...linesToTest, ...lines];
     });
     bufferedLine.on('close', () => {
-      expect(linesToTest).toEqual(['line one', 'line two']);
-      done();
-    });
-  });
-
-  test('it can read two lines using a buffer size of 1', (done) => {
-    const input = new TestReadable();
-    input.push('line one\n');
-    input.push('line two\n');
-    input.push(null);
-    const bufferedLine = new BufferLines({ bufferSize: 1, input });
-    let linesToTest: string[] = [];
-    bufferedLine.on('lines', (lines: string[]) => {
-      linesToTest = [...linesToTest, ...lines];
-    });
-    bufferedLine.on('close', () => {
-      expect(linesToTest).toEqual(['line one', 'line two']);
+      expect(linesToTest).toEqual([]);
       done();
     });
   });
 
-  test('two identical lines are collapsed into just one line without duplicates', (done) => {
+  test('it can read 200 lines', (done) => {
     const input = new TestReadable();
-    input.push('line one\n');
-    input.push('line one\n');
-    input.push(null);
     const bufferedLine = new BufferLines({ bufferSize: IMPORT_BUFFER_SIZE, input });
+    input.push('--boundary\n');
+    input.push('Content-type: text/plain\n');
+    input.push('Content-Disposition: form-data; name="fieldName"; filename="filename.text"\n');
+    input.push('\n');
     let linesToTest: string[] = [];
-    bufferedLine.on('lines', (lines: string[]) => {
-      linesToTest = [...linesToTest, ...lines];
-    });
-    bufferedLine.on('close', () => {
-      expect(linesToTest).toEqual(['line one']);
-      done();
-    });
-  });
-
-  test('it can close out without writing any lines', (done) => {
-    const input = new TestReadable();
+    const size200: string[] = new Array(200).fill(null).map((_, index) => `${index}\n`);
+    size200.forEach((element) => input.push(element));
+    input.push('--boundary--\n');
     input.push(null);
-    const bufferedLine = new BufferLines({ bufferSize: IMPORT_BUFFER_SIZE, input });
-    let linesToTest: string[] = [];
     bufferedLine.on('lines', (lines: string[]) => {
       linesToTest = [...linesToTest, ...lines];
     });
     bufferedLine.on('close', () => {
-      expect(linesToTest).toEqual([]);
+      expect(linesToTest.length).toEqual(200);
       done();
     });
   });
 
-  test('it can read 200 lines', (done) => {
+  test('it can read an example multi-part message', (done) => {
     const input = new TestReadable();
+    input.push('--boundary\n');
+    input.push('Content-type: text/plain\n');
+    input.push('Content-Disposition: form-data; name="fieldName"; filename="filename.text"\n');
+    input.push('\n');
+    input.push('127.0.0.1\n');
+    input.push('127.0.0.2\n');
+    input.push('127.0.0.3\n');
+    input.push('\n');
+    input.push('--boundary--\n');
+    input.push(null);
     const bufferedLine = new BufferLines({ bufferSize: IMPORT_BUFFER_SIZE, input });
     let linesToTest: string[] = [];
-    const size200: string[] = new Array(200).fill(null).map((_, index) => `${index}\n`);
-    size200.forEach((element) => input.push(element));
-    input.push(null);
     bufferedLine.on('lines', (lines: string[]) => {
       linesToTest = [...linesToTest, ...lines];
     });
     bufferedLine.on('close', () => {
-      expect(linesToTest.length).toEqual(200);
+      expect(linesToTest).toEqual(['127.0.0.1', '127.0.0.2', '127.0.0.3']);
       done();
     });
   });
 
-  test('it can read an example multi-part message', (done) => {
+  test('it does not create empty values for lines after the end boundary', (done) => {
     const input = new TestReadable();
     input.push('--boundary\n');
     input.push('Content-type: text/plain\n');
@@ -142,6 +113,7 @@ describe('buffer_lines', () => {
     input.push('127.0.0.3\n');
     input.push('\n');
     input.push('--boundary--\n');
+    input.push('\n');
     input.push(null);
     const bufferedLine = new BufferLines({ bufferSize: IMPORT_BUFFER_SIZE, input });
     let linesToTest: string[] = [];
diff --git a/x-pack/plugins/lists/server/services/items/buffer_lines.ts b/x-pack/plugins/lists/server/services/items/buffer_lines.ts
index cb6d073010127..e179fc4358468 100644
--- a/x-pack/plugins/lists/server/services/items/buffer_lines.ts
+++ b/x-pack/plugins/lists/server/services/items/buffer_lines.ts
@@ -48,7 +48,7 @@ export class BufferLines extends Readable {
         // we are at the end of the stream
         this.boundary = null;
         this.readableText = false;
-      } else {
+      } else if (this.readableText) {
         // we have actual content to push
         this.push(line);
       }
diff --git a/x-pack/plugins/lists/server/services/items/write_lines_to_bulk_list_items.test.ts b/x-pack/plugins/lists/server/services/items/write_lines_to_bulk_list_items.test.ts
index 78098fde59827..89c3d89fe631e 100644
--- a/x-pack/plugins/lists/server/services/items/write_lines_to_bulk_list_items.test.ts
+++ b/x-pack/plugins/lists/server/services/items/write_lines_to_bulk_list_items.test.ts
@@ -49,6 +49,12 @@ describe('write_lines_to_bulk_list_items', () => {
     test('It imports a set of items to a write buffer by calling "getListItemByValues" with a single value given', async () => {
       const options = getImportListItemsToStreamOptionsMock();
       const promise = importListItemsToStream(options);
+      options.stream.push('--boundary\n');
+      options.stream.push('Content-type: text/plain\n');
+      options.stream.push(
+        'Content-Disposition: form-data; name="fieldName"; filename="filename.text"\n'
+      );
+      options.stream.push('\n');
       options.stream.push('127.0.0.1\n');
       options.stream.push(null);
       await promise;
@@ -58,6 +64,12 @@ describe('write_lines_to_bulk_list_items', () => {
     test('It imports a set of items to a write buffer by calling "getListItemByValues" with two values given', async () => {
       const options = getImportListItemsToStreamOptionsMock();
       const promise = importListItemsToStream(options);
+      options.stream.push('--boundary\n');
+      options.stream.push('Content-type: text/plain\n');
+      options.stream.push(
+        'Content-Disposition: form-data; name="fieldName"; filename="filename.text"\n'
+      );
+      options.stream.push('\n');
       options.stream.push('127.0.0.1\n');
       options.stream.push('127.0.0.2\n');
       options.stream.push(null);