diff --git a/lib/datasource/readme.md b/lib/datasource/readme.md
index a126207adf1158c4a56311f8dbeffdc543c93ccd..adb34705e78eda9f8d6e7ee84c39738da4a3eea0 100644
--- a/lib/datasource/readme.md
+++ b/lib/datasource/readme.md
@@ -9,7 +9,6 @@ The minimum exported interface for a datasource is a function called `getPkgRele
 The `purl` object contains:
 
 - `lookupName`: the package's full name including scope if present (e.g. `@foo/bar`)
-- `qualifiers`: optional addition arguments, may contain fields like `registry`
 
 In the simplest case, the datasource only needs to pay attention to `purl.lookupName`.
 
diff --git a/test/datasource/docker.spec.js b/test/datasource/docker.spec.js
index 4304a5da6739f6abe863c0ff23192558609ff510..4399136459f2dde176d888a0bff734121d8651be 100644
--- a/test/datasource/docker.spec.js
+++ b/test/datasource/docker.spec.js
@@ -231,7 +231,6 @@ describe('api/docker', () => {
       got.mockReturnValueOnce({});
       const res = await docker.getPkgReleases({
         lookupName: 'my/node',
-        qualifiers: {},
       });
       expect(res).toBe(null);
     });