diff --git a/bob/learn/tensorflow/trainers/Trainer.py b/bob/learn/tensorflow/trainers/Trainer.py
index a71997ca735761b5372ef1a7f44ceb08fcc2e104..0ad5b4892f5bcb9d1e26f9481e92de453ecf9fe5 100644
--- a/bob/learn/tensorflow/trainers/Trainer.py
+++ b/bob/learn/tensorflow/trainers/Trainer.py
@@ -332,7 +332,8 @@ class Trainer(object):
 
         logger.info("Initializing !!")
 
-        config = tf.ConfigProto(log_device_placement=True)
+        config = tf.ConfigProto(log_device_placement=True,
+                                gpu_options=tf.GPUOptions(per_process_gpu_memory_fraction=0.333))
         config.gpu_options.allow_growth = True
 
         # Pickle the architecture to save