diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 2d1f3b2e..ba99a264 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -115,6 +115,8 @@ steps:
       includeRootFolder: false
       archiveType: zip
       archiveFile: $(Build.StagingDirectory)\vscode-arduino.vsix
+  - script: python .\build\markExecutableFiles.py
+    displayName: Make serial monitor executable
   - task: MSBuild@1
     displayName: Sign VSIX
     inputs:
diff --git a/build/markExecutableFiles.py b/build/markExecutableFiles.py
new file mode 100644
index 00000000..89213be5
--- /dev/null
+++ b/build/markExecutableFiles.py
@@ -0,0 +1,31 @@
+import os
+import zipfile
+
+staging_directory = os.getenv('BUILD_STAGINGDIRECTORY')
+input_archive_path = f"{staging_directory}/vscode-arduino.vsix"
+output_archive_path = f"{staging_directory}/vscode-arduino-out.vsix"
+
+filenames = [
+    "extension/out/serial-monitor-cli/darwin/main",
+    "extension/out/serial-monitor-cli/linux/main"
+]
+
+input_archive = zipfile.ZipFile(input_archive_path, 'r')
+output_archive = zipfile.ZipFile(output_archive_path, 'w')
+
+executable_count = 0
+for info in input_archive.infolist():
+    data = input_archive.read(info)
+    if info.filename in filenames:
+        # Magic number from from https://stackoverflow.com/a/48435482
+        info.external_attr = 0o100755 << 16
+        executable_count += 1
+    output_archive.writestr(info, data)
+
+if executable_count != len(filenames):
+    raise Exception(f'Expected to find {len(filenames)} executables but only found {executable_count}')
+
+input_archive.close()
+output_archive.close()
+
+os.replace(output_archive_path, input_archive_path)