diff --git a/.drone.star b/.drone.star
index b82577b2b..25420c3d3 100644
--- a/.drone.star
+++ b/.drone.star
@@ -357,7 +357,12 @@ def uploadScanResults(ctx):
             "SONAR_PULL_REQUEST_KEY": "%s" % (ctx.build.ref.replace("refs/pull/", "").split("/")[0]),
         })
 
-    repo_slug = ctx.build.source_repo if ctx.build.source_repo else ctx.repo.slug
+    fork_handling = []
+    if ctx.build.source_repo != "" and ctx.build.source_repo != ctx.repo.slug:
+        fork_handling = [
+            "git remote add fork https://github.com/%s.git" % (ctx.build.source_repo),
+            "git fetch fork",
+        ]
 
     return {
         "kind": "pipeline",
@@ -375,9 +380,13 @@ def uploadScanResults(ctx):
                 "name": "clone",
                 "image": "alpine/git:latest",
                 "commands": [
-                    "git clone https://github.com/%s.git ." % (repo_slug),
-                    "git checkout $DRONE_COMMIT",
-                ],
+                                # Always use the owncloud/ocis repository as base to have an up to date default branch.
+                                # This is needed for the skipIfUnchanged step, since it references a commit on master (which could be absent on a fork)
+                                "git clone https://github.com/%s.git ." % (ctx.repo.slug),
+                            ] + fork_handling +
+                            [
+                                "git checkout $DRONE_COMMIT",
+                            ],
             },
         ] + skipIfUnchanged(ctx, "unit-tests") + [
             {