diff --git a/bob/bio/base/pipelines/vanilla_biometrics/legacy.py b/bob/bio/base/pipelines/vanilla_biometrics/legacy.py
index 3dd74ec709e29b76cb3f1fae28bd4b6addf09a2b..f1279b05e34030e2b3b5a300639fdfc833c843cf 100644
--- a/bob/bio/base/pipelines/vanilla_biometrics/legacy.py
+++ b/bob/bio/base/pipelines/vanilla_biometrics/legacy.py
@@ -169,7 +169,7 @@ class BioAlgorithmLegacy(BioAlgorithm):
     Parameters
     ----------
       instance: object
-         Callable function that instantiates the :any:`bob.bio.base.algorithm.Algorithm`
+         An instance of :any:`bob.bio.base.algorithm.Algorithm`
 
 
     Example
diff --git a/bob/bio/base/transformers/algorithm.py b/bob/bio/base/transformers/algorithm.py
index b60adf4aac9baff83f9836d75fea8a53d9e4464b..68e55d3846597e97f2ac47e4f91f539e2d1b6b07 100644
--- a/bob/bio/base/transformers/algorithm.py
+++ b/bob/bio/base/transformers/algorithm.py
@@ -27,7 +27,7 @@ class AlgorithmTransformer(TransformerMixin, BaseEstimator):
     Parameters
     ----------
       instance: object
-         Callable function that instantiates the bob.bio.base.algorithm.Algorithm
+         An instance of bob.bio.base.algorithm.Algorithm
 
     """
 
diff --git a/bob/bio/base/transformers/extractor.py b/bob/bio/base/transformers/extractor.py
index bad554c2834c8e8cb149a57b8fa9eacd1e8e1bae..c25bcfd942f4a2c43a68469dbc82eededaa8e817 100644
--- a/bob/bio/base/transformers/extractor.py
+++ b/bob/bio/base/transformers/extractor.py
@@ -14,7 +14,7 @@ class ExtractorTransformer(TransformerMixin, BaseEstimator):
     ----------
 
       instance: object
-         Instance of `bob.bio.base.extractor.Extractor`
+         An instance of `bob.bio.base.extractor.Extractor`
 
       model_path: ``str``
          Model path in case :any:`bob.bio.base.extractor.Extractor.requires_training` is equals to true
diff --git a/bob/bio/base/transformers/preprocessor.py b/bob/bio/base/transformers/preprocessor.py
index fcb5dfab37b8ac2f2e687d7e67286c535aa017ed..1b1e15c2a2c6d4552e791a70b642db6d0653faeb 100644
--- a/bob/bio/base/transformers/preprocessor.py
+++ b/bob/bio/base/transformers/preprocessor.py
@@ -12,7 +12,7 @@ class PreprocessorTransformer(TransformerMixin, BaseEstimator):
     ----------
 
       instance: object
-         Instance of `bob.bio.base.preprocessor.Preprocessor`
+         An instance of `bob.bio.base.preprocessor.Preprocessor`
 
 
     """