diff --git a/bibigrid/core/actions/list_clusters.py b/bibigrid/core/actions/list_clusters.py
index 99e1b6bc..554b7221 100644
--- a/bibigrid/core/actions/list_clusters.py
+++ b/bibigrid/core/actions/list_clusters.py
@@ -24,8 +24,8 @@ def dict_clusters(providers, log):
         servers = provider.list_servers()
         for server in servers:
             result = SERVER_REGEX.match(server["name"])
-            print(server["name"])
-            print(result)
+            log.log(42, server["name"])
+            log.log(42, result)
             if result:
                 identifier = result.group(4) or result.group(2)
                 cluster_id = result.group(5) or result.group(3)
@@ -71,7 +71,7 @@ def log_list(cluster_id, providers, log):
             master_count, worker_count, vpn_count = get_size_overview(cluster_dict[cluster_id], log)
             log.log(42, f"\tCluster has {master_count} master, {vpn_count} vpngtw and {worker_count} regular workers. "
                        f"The cluster is spread over {vpn_count + master_count} reachable provider(s).")
-            pprint.pprint(cluster_dict[cluster_id])
+            log.log(42, pprint.pformat(cluster_dict[cluster_id]))
         else:
             log.info("Cluster with cluster-id {cluster_id} not found.")
             log.log(42, f"Cluster with cluster-id {cluster_id} not found.")
diff --git a/bibigrid/core/utility/validate_configuration.py b/bibigrid/core/utility/validate_configuration.py
index 72deb806..a4232d2e 100644
--- a/bibigrid/core/utility/validate_configuration.py
+++ b/bibigrid/core/utility/validate_configuration.py
@@ -303,8 +303,8 @@ def check_instance_type_image_combination(self, instance_type, instance_image, p
         flavor = provider.get_flavor(instance_type)
         if not flavor:
             self.log.warning("Flavor %s does not exist.", instance_type)
-            print("Available flavors:")
-            print("\n".join(provider.get_active_flavors()))
+            self.log.log(42, "Available flavors:")
+            self.log.log(42, "\n".join(provider.get_active_flavors()))
             return False
         type_max_disk_space = flavor["disk"]
         type_max_ram = flavor["ram"]