diff --git a/quacc/evaluation/comp.py b/quacc/evaluation/comp.py
index 344b9fd..0cd71d0 100644
--- a/quacc/evaluation/comp.py
+++ b/quacc/evaluation/comp.py
@@ -12,7 +12,7 @@ from quacc.dataset import Dataset
 from quacc.environment import env
 from quacc.evaluation import baseline, method
 from quacc.evaluation.report import CompReport, DatasetReport
-from quacc.evaluation.worker import estimate_worker
+from quacc.evaluation.worker import WorkerArgs, estimate_worker
 from quacc.logger import Logger
 
 pd.set_option("display.float_format", "{:.4f}".format)
@@ -91,45 +91,42 @@ def evaluate_comparison(dataset: Dataset, estimators=None) -> DatasetReport:
             log.info(
                 f"Dataset sample {d.train_prev[1]:.2f} of dataset {dataset.name} started"
             )
-            tstart = time.time()
             tasks = [
-                (estim, d.train, d.validation, d.test) for estim in CE.func[estimators]
+                WorkerArgs(
+                    _estimate=estim,
+                    train=d.train,
+                    validation=d.validation,
+                    test=d.test,
+                    _env=env,
+                    q=Logger.queue(),
+                )
+                for estim in CE.func[estimators]
             ]
-            results = [
-                pool.apply_async(estimate_worker, t, {"_env": env, "q": Logger.queue()})
-                for t in tasks
-            ]
-
-            results_got = []
-            for _r in results:
-                try:
-                    r = _r.get()
-                    if r["result"] is not None:
-                        results_got.append(r)
-                except Exception as e:
-                    log.warning(
-                        f"Dataset sample {d.train_prev[1]:.2f} of dataset {dataset.name} failed. Exception: {e}"
-                    )
-
-            tend = time.time()
-            times = {r["name"]: r["time"] for r in results_got}
-            times["tot"] = tend - tstart
-            log.info(
-                f"Dataset sample {d.train_prev[1]:.2f} of dataset {dataset.name} finished [took {times['tot']:.4f}s]"
-            )
             try:
+                tstart = time.time()
+                results = [
+                    r for r in pool.imap(estimate_worker, tasks) if r is not None
+                ]
+
+                g_time = time.time() - tstart
+                log.info(
+                    f"Dataset sample {d.train_prev[1]:.2f} of dataset {dataset.name} finished "
+                    f"[took {g_time:.4f}s]"
+                )
+
                 cr = CompReport(
-                    [r["result"] for r in results_got],
+                    results,
                     name=dataset.name,
                     train_prev=d.train_prev,
                     valid_prev=d.validation_prev,
-                    times=times,
+                    g_time=g_time,
                 )
+                dr += cr
+
             except Exception as e:
                 log.warning(
-                    f"Dataset sample {d.train_prev[1]:.2f} of dataset {dataset.name} failed. Exception: {e}"
+                    f"Dataset sample {d.train_prev[1]:.2f} of dataset {dataset.name} failed. "
+                    f"Exception: {e}"
                 )
                 traceback(e)
-                cr = None
-            dr += cr
     return dr
diff --git a/quacc/evaluation/worker.py b/quacc/evaluation/worker.py
index e1d02b0..681c597 100644
--- a/quacc/evaluation/worker.py
+++ b/quacc/evaluation/worker.py
@@ -1,44 +1,52 @@
 import time
+from dataclasses import dataclass
+from multiprocessing import Queue
 from traceback import print_exception as traceback
 
 import quapy as qp
+from quapy.data import LabelledCollection
 from quapy.protocol import APP
 from sklearn.linear_model import LogisticRegression
 
+from quacc.environment import env, environ
 from quacc.logger import SubLogger
 
 
-def estimate_worker(_estimate, train, validation, test, _env=None, q=None):
-    qp.environ["SAMPLE_SIZE"] = _env.SAMPLE_SIZE
-    SubLogger.setup(q)
-    log = SubLogger.logger()
+@dataclass(frozen=True)
+class WorkerArgs:
+    _estimate: callable
+    train: LabelledCollection
+    validation: LabelledCollection
+    test: LabelledCollection
+    _env: environ
+    q: Queue
 
-    model = LogisticRegression()
 
-    model.fit(*train.Xy)
-    protocol = APP(
-        test,
-        n_prevalences=_env.PROTOCOL_N_PREVS,
-        repeats=_env.PROTOCOL_REPEATS,
-        return_type="labelled_collection",
-    )
-    start = time.time()
-    try:
-        result = _estimate(model, validation, protocol)
-    except Exception as e:
-        log.warning(f"Method {_estimate.__name__} failed. Exception: {e}")
-        traceback(e)
-        return {
-            "name": _estimate.__name__,
-            "result": None,
-            "time": 0,
-        }
+def estimate_worker(args: WorkerArgs):
+    with env.load(args._env):
+        qp.environ["SAMPLE_SIZE"] = env.SAMPLE_SIZE
+        SubLogger.setup(args.q)
+        log = SubLogger.logger()
 
-    end = time.time()
-    log.info(f"{_estimate.__name__} finished [took {end-start:.4f}s]")
+        model = LogisticRegression()
 
-    return {
-        "name": _estimate.__name__,
-        "result": result,
-        "time": end - start,
-    }
+        model.fit(*args.train.Xy)
+        protocol = APP(
+            args.test,
+            n_prevalences=env.PROTOCOL_N_PREVS,
+            repeats=env.PROTOCOL_REPEATS,
+            return_type="labelled_collection",
+            random_state=env._R_SEED,
+        )
+        start = time.time()
+        try:
+            result = args._estimate(model, args.validation, protocol)
+        except Exception as e:
+            log.warning(f"Method {args._estimate.name} failed. Exception: {e}")
+            traceback(e)
+            return None
+
+        result.time = time.time() - start
+        log.info(f"{args._estimate.name} finished [took {result.time:.4f}s]")
+
+        return result