diff --git a/deepspeech/exps/deepspeech2/model.py b/deepspeech/exps/deepspeech2/model.py
index b854a996966efc608e3a2ce08019eacf216f677c..e84de61574be3040db674d21215fbee89e5f0bc9 100644
--- a/deepspeech/exps/deepspeech2/model.py
+++ b/deepspeech/exps/deepspeech2/model.py
@@ -235,16 +235,18 @@ class DeepSpeech2Trainer(Trainer):
             num_workers=config.collator.num_workers)
         self.valid_loader = DataLoader(
             dev_dataset,
-            batch_size=int(config.collator.batch_size / 4),
+            batch_size=int(config.collator.batch_size),
             shuffle=False,
             drop_last=False,
-            collate_fn=collate_fn_dev)
+            collate_fn=collate_fn_dev,
+            num_workers=config.collator.num_workers)
         self.test_loader = DataLoader(
             test_dataset,
             batch_size=config.decoding.batch_size,
             shuffle=False,
             drop_last=False,
-            collate_fn=collate_fn_test)
+            collate_fn=collate_fn_test,
+            num_workers=config.collator.num_workers)
         logger.info("Setup train/valid/test  Dataloader!")
 
 
diff --git a/deepspeech/exps/u2/model.py b/deepspeech/exps/u2/model.py
index 1afd9b101889086d2d806f0a15e03f89c19284aa..c30f324b9ae6eddfb3b7a1a4a1101745e44520bd 100644
--- a/deepspeech/exps/u2/model.py
+++ b/deepspeech/exps/u2/model.py
@@ -292,7 +292,8 @@ class U2Trainer(Trainer):
             batch_size=config.collator.batch_size,
             shuffle=False,
             drop_last=False,
-            collate_fn=collate_fn_dev)
+            collate_fn=collate_fn_dev,
+            num_workers=config.collator.num_workers, )
 
         # test dataset, return raw text
         config.data.manifest = config.data.test_manifest
@@ -314,7 +315,8 @@ class U2Trainer(Trainer):
             batch_size=config.decoding.batch_size,
             shuffle=False,
             drop_last=False,
-            collate_fn=SpeechCollator.from_config(config))
+            collate_fn=SpeechCollator.from_config(config),
+            num_workers=config.collator.num_workers, )
         # return text token id
         config.collator.keep_transcription_text = False
         self.align_loader = DataLoader(
@@ -322,7 +324,8 @@ class U2Trainer(Trainer):
             batch_size=config.decoding.batch_size,
             shuffle=False,
             drop_last=False,
-            collate_fn=SpeechCollator.from_config(config))
+            collate_fn=SpeechCollator.from_config(config),
+            num_workers=config.collator.num_workers, )
         logger.info("Setup train/valid/test/align Dataloader!")
 
     def setup_model(self):
diff --git a/deepspeech/exps/u2_st/model.py b/deepspeech/exps/u2_st/model.py
index 9a34cbdc2948a6df6ab9322f9a5eff31ce6b4917..c480499c7b397ff12eb4f7d5047101168a33d149 100644
--- a/deepspeech/exps/u2_st/model.py
+++ b/deepspeech/exps/u2_st/model.py
@@ -292,7 +292,8 @@ class U2STTrainer(Trainer):
             batch_size=config.collator.batch_size,
             shuffle=False,
             drop_last=False,
-            collate_fn=collate_fn_dev)
+            collate_fn=collate_fn_dev,
+            num_workers=config.collator.num_workers, )
 
         # test dataset, return raw text
         config.data.manifest = config.data.test_manifest
@@ -313,7 +314,8 @@ class U2STTrainer(Trainer):
             batch_size=config.decoding.batch_size,
             shuffle=False,
             drop_last=False,
-            collate_fn=TestCollator.from_config(config))
+            collate_fn=TestCollator.from_config(config),
+            num_workers=config.collator.num_workers, )
         # return text token id
         config.collator.keep_transcription_text = False
         self.align_loader = DataLoader(
@@ -321,7 +323,8 @@ class U2STTrainer(Trainer):
             batch_size=config.decoding.batch_size,
             shuffle=False,
             drop_last=False,
-            collate_fn=TestCollator.from_config(config))
+            collate_fn=TestCollator.from_config(config),
+            num_workers=config.collator.num_workers, )
         logger.info("Setup train/valid/test/align Dataloader!")
 
     def setup_model(self):