diff --git a/bob/bio/base/pipelines/vanilla_biometrics/annotated_legacy.py b/bob/bio/base/pipelines/vanilla_biometrics/annotated_legacy.py
index 25392a2515f36ebaabb11b35072f7864ad28ebf1..91f8d4877bfdcce451b4495ffec265dc61cf104a 100644
--- a/bob/bio/base/pipelines/vanilla_biometrics/annotated_legacy.py
+++ b/bob/bio/base/pipelines/vanilla_biometrics/annotated_legacy.py
@@ -15,6 +15,10 @@ import bob.io.base
 from .legacy import DatabaseConnector
 from .blocks import SampleLoader
 from bob.pipelines.sample.sample import SampleSet, DelayedSample, Sample 
+from bob.pipelines.utils import is_picklable
+
+import logging
+logger = logging.getLogger("bob.bio.base")
 
 
 class DatabaseConnectorAnnotated(DatabaseConnector):
@@ -293,19 +297,28 @@ class SampleLoaderAnnotated(SampleLoader):
                 # because we are checkpointing, we return a DelayedSample
                 # instead of normal (preloaded) sample. This allows the next
                 # phase to avoid loading it would it be unnecessary (e.g. next
-                # phase is already check-pointed)                
-                #reader = bob.io.base.load
+                # phase is already check-pointed)
                 reader = (
                     getattr(func, "read_data")
                     if hasattr(func, "read_data")
                     else getattr(func, "read_feature")
-                )
-                reader = reader.__func__ # The reader object might not be picklable
-                samples.append(
-                    DelayedSample(
-                        functools.partial(reader, None, candidate), parent=s
+                )                
+                if is_picklable(reader):
+                    samples.append(
+                        DelayedSample(
+                            functools.partial(reader, candidate), parent=s
+                        )
                     )
-                )
+                else:                    
+                    logger.warning(f"The method {reader} is not picklable. Shiping its unbounded method to `DelayedSample`.")
+                    reader = reader.__func__ # The reader object might not be picklable
+
+                    samples.append(
+                        DelayedSample(
+                            functools.partial(reader, None, candidate), parent=s
+                        )
+                    )
+
         else:
             # if checkpointing is not required, load the data and preprocess it
             # as we would normally do
diff --git a/bob/bio/base/pipelines/vanilla_biometrics/blocks.py b/bob/bio/base/pipelines/vanilla_biometrics/blocks.py
index 0e0c9b7f7a6c34a4adb5f98307a51735b5ca27da..88390c13323b78ed7d69cddd5c9abcb7833b3fbd 100644
--- a/bob/bio/base/pipelines/vanilla_biometrics/blocks.py
+++ b/bob/bio/base/pipelines/vanilla_biometrics/blocks.py
@@ -7,8 +7,11 @@ import numpy
 import os
 import bob.io.base
 from bob.pipelines.sample.sample import DelayedSample, SampleSet, Sample
+from bob.pipelines.utils import is_picklable
 
 """Re-usable blocks for legacy bob.bio.base algorithms"""
+import logging
+logger = logging.getLogger("bob.bio.base")
 
 
 class SampleLoader:
@@ -107,10 +110,21 @@ class SampleLoader:
                     if hasattr(func, "read_data")
                     else getattr(func, "read_feature")
                 )
-                reader = reader.__func__ # The reader object might not be picklable
-                samples.append(
-                    DelayedSample(functools.partial(reader, None, candidate), parent=s)
-                )
+                if is_picklable(reader):
+                    samples.append(
+                        DelayedSample(
+                            functools.partial(reader, candidate), parent=s
+                        )
+                    )
+                else:                    
+                    logger.warning(f"The method {func} is not picklable. Shiping its unbounded method to `DelayedSample`.")
+                    reader = reader.__func__ # The reader object might not be picklable
+
+                    samples.append(
+                        DelayedSample(
+                            functools.partial(reader, None, candidate), parent=s
+                        )
+                    )
         else:
             # if checkpointing is not required, load the data and preprocess it
             # as we would normally do