diff --git a/bob/bio/base/algorithm/Algorithm.py b/bob/bio/base/algorithm/Algorithm.py
index 696e602d16a6e744f5ff0dc21255eb31af9b5f75..f031664505baa7481cbc0368ed0bc1755e6f9269 100644
--- a/bob/bio/base/algorithm/Algorithm.py
+++ b/bob/bio/base/algorithm/Algorithm.py
@@ -91,7 +91,10 @@ class Algorithm (object):
   ):
 
     
-    warnings.warn("bob.bio.base.Algorithm is Deprecated", DeprecationWarning)
+    warnings.simplefilter('default')
+    warnings.warn("`bob.bio.base.algorithm.Algorithm` will be deprecated in 01/01/2021. "\
+                  "Please, implement your biometric algorithm using `bob.pipelines` (https://gitlab.idiap.ch/bob/bob.pipelines).", DeprecationWarning)
+
 
 
     self.performs_projection = performs_projection
diff --git a/bob/bio/base/extractor/Extractor.py b/bob/bio/base/extractor/Extractor.py
index fc09fb62135f97465942d16e75dd576631aa523e..c37e4439f42a98e33f2e17e607d44e93fca49004 100644
--- a/bob/bio/base/extractor/Extractor.py
+++ b/bob/bio/base/extractor/Extractor.py
@@ -53,6 +53,10 @@ class Extractor (object):
     self.min_feature_file_size = min_feature_file_size
     self._kwargs = kwargs
 
+    warnings.simplefilter('default')
+    warnings.warn("`bob.bio.base.extractor.Extractor` will be deprecated in 01/01/2021. "\
+                  "Please, implement your biometric algorithm using `bob.pipelines` (https://gitlab.idiap.ch/bob/bob.pipelines).", DeprecationWarning)
+
 
   ############################################################
   ### functions that must be overwritten in derived classes
diff --git a/bob/bio/base/preprocessor/Preprocessor.py b/bob/bio/base/preprocessor/Preprocessor.py
index c1e1aeeebdbe76310213447f07a965fffc5acda2..dc5d7e47573c209744254a560fb17196c723439d 100644
--- a/bob/bio/base/preprocessor/Preprocessor.py
+++ b/bob/bio/base/preprocessor/Preprocessor.py
@@ -39,7 +39,12 @@ class Preprocessor (object):
         self.read_original_data = read_original_data
         self.min_preprocessed_file_size = min_preprocessed_file_size
         self._kwargs = kwargs
-        pass
+
+        warnings.simplefilter('default')
+        warnings.warn("`bob.bio.base.preprocessor.Preprocessor` will be deprecated in 01/01/2021. "\
+                      "Please, implement your biometric algorithm using `bob.pipelines` (https://gitlab.idiap.ch/bob/bob.pipelines).", DeprecationWarning)
+
+
 
     # The call function (i.e. the operator() in C++ terms)
     def __call__(self, data, annotations):