diff --git a/HISTORY.rst b/HISTORY.rst
index a0ac578b..53db423c 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -13,6 +13,7 @@ PlatformIO Core 5
 
 - Fixed an issue when using a custom git/ssh package with `platform_packages <https://docs.platformio.org/page/projectconf/section_env_platform.html#platform-packages>`__ option (`issue #3624 <https://github.com/platformio/platformio-core/issues/3624>`_)
 - Fixed an issue with "ImportError: cannot import name '_get_backend' from 'cryptography.hazmat.backends'" when using `Remote Development <https://docs.platformio.org/page/plus/pio-remote.html>`__ on RaspberryPi device (`issue #3652 <https://github.com/platformio/platformio-core/issues/3652>`_)
+- Fixed an issue when `pio package unpublish <https://docs.platformio.org/page/core/userguide/package/cmd_unpublish.html>`__ command crashes (`issue #3660 <https://github.com/platformio/platformio-core/issues/3660>`_)
 
 5.0.0 (2020-09-03)
 ~~~~~~~~~~~~~~~~~~
diff --git a/platformio/commands/package.py b/platformio/commands/package.py
index 88f6c0d3..f62362ff 100644
--- a/platformio/commands/package.py
+++ b/platformio/commands/package.py
@@ -107,7 +107,7 @@ def package_unpublish(package, type, undo):  # pylint: disable=redefined-builtin
         type=type,
         name=spec.name,
         owner=spec.owner,
-        version=spec.requirements,
+        version=str(spec.requirements),
         undo=undo,
     )
     click.secho(response.get("message"), fg="green")