diff --git a/services/pypi/pypi-helpers.js b/services/pypi/pypi-helpers.js
index 636e1f0f21a61f23ab7de2f739260f25f7d6320c..a57ea9c4f77af5155d24036e06b5653228061ec2 100644
--- a/services/pypi/pypi-helpers.js
+++ b/services/pypi/pypi-helpers.js
@@ -50,6 +50,16 @@ function getLicenses(packageData) {
   const {
     info: { license },
   } = packageData
+
+  /*
+  The .license field may either contain
+  - a short license description (e.g: 'MIT' or 'GPL-3.0') or
+  - the full text of a license
+  but there is nothing in the response that tells us explicitly.
+  We have to make an assumption based on the length.
+  See https://github.com/badges/shields/issues/8689 and
+  https://github.com/badges/shields/pull/8690 for more info.
+  */
   if (license && license.length < 40) {
     return [license]
   } else {