diff --git a/CHANGELOG.md b/CHANGELOG.md
index f1a9fdcb..e7388032 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@
 
 ### Changed
 
+- Non-existing users and teams will now trigger a warning message rather a failure during the execution of an `apply` operation. ([#51](https://gitlab.eclipse.org/eclipsefdn/security/otterdog/-/issues/51))
 - Prevent printing of credential data when trace mode is enabled. ([#47](https://gitlab.eclipse.org/eclipsefdn/security/otterdog/-/issues/47))
 - Switching to module `click` for command line parsing.
 - Updated module `playwright` to version 1.33.0.
diff --git a/otterdog/providers/github/__init__.py b/otterdog/providers/github/__init__.py
index ba7d2760..46ccc3eb 100644
--- a/otterdog/providers/github/__init__.py
+++ b/otterdog/providers/github/__init__.py
@@ -163,9 +163,16 @@ def get_actor_ids(self, actor_names: list[str]) -> list[str]:
         result = []
         for actor in actor_names:
             if actor.startswith("/"):
-                result.append(self.rest_client.get_user_node_id(actor[1:]))
+                try:
+                    result.append(self.rest_client.get_user_node_id(actor[1:]))
+                except RuntimeError:
+                    utils.print_warn(f"user '{actor}' does not exist, skipping")
+
             else:
-                result.append(self.rest_client.get_team_node_id(actor))
+                try:
+                    result.append(self.rest_client.get_team_node_id(actor))
+                except RuntimeError:
+                    utils.print_warn(f"team '{actor}' does not exist, skipping")
 
         return result