diff --git a/tests/test_features_settings.py b/tests/test_features_settings.py
index 943cbda..6d5b533 100644
--- a/tests/test_features_settings.py
+++ b/tests/test_features_settings.py
@@ -14,8 +14,6 @@
 
 settings4 = tsfel.get_features_by_domain(None)
 
-# settings5 = tsfel.extract_sheet('Features')
-
 settings6 = tsfel.get_features_by_tag("audio")
 
 settings7 = tsfel.get_features_by_tag("inertial")
diff --git a/tsfel/feature_extraction/features.py b/tsfel/feature_extraction/features.py
index 866635f..75cbf5f 100644
--- a/tsfel/feature_extraction/features.py
+++ b/tsfel/feature_extraction/features.py
@@ -12,6 +12,10 @@
     + str(FEATURES_MIN_SIZE)
     + " data points."
 )
+
+future_warn_flag = False
+warnings.simplefilter("once", FutureWarning)
+
 # ############################################# TEMPORAL DOMAIN ##################################################### #
 
 
@@ -488,6 +492,16 @@ def hist(signal, nbins=10, r=1):
     nd-array
         The values of the histogram
     """
+    global future_warn_flag
+
+    if not future_warn_flag:
+        warnings.warn(
+            ("The histogram feature was deprecated in version 0.1.8 and will be replaced by the mode of histogram in 0.1.9."
+            " From then on, only a single feature value will be returned."), 
+            FutureWarning
+        )
+        future_warn_flag = True
+    
     # TODO: r value must be revised!
     histsig, bin_edges = np.histogram(signal, bins=nbins, range=[-r, r])
 
diff --git a/tsfel/feature_extraction/features_settings.py b/tsfel/feature_extraction/features_settings.py
index f4b499d..8f22265 100644
--- a/tsfel/feature_extraction/features_settings.py
+++ b/tsfel/feature_extraction/features_settings.py
@@ -42,23 +42,42 @@ def get_features_by_domain(domain=None, json_path=None):
     Dict
         Dictionary with the features settings
     """
+        
+    valid_domains = ["statistical", "temporal", "spectral", "fractal", "all"]
 
     if json_path is None:
         json_path = tsfel.__path__[0] + "/feature_extraction/features.json"
 
-        if domain not in ["statistical", "temporal", "spectral", "fractal", None]:
-            raise SystemExit(
-                "No valid domain. Choose: statistical, temporal, spectral, fractal or None (for all feature settings).",
+        if isinstance(domain, str) and domain not in valid_domains:
+            raise ValueError(
+                f"Domain {domain} is invalid. Please choose from `statistical`, `temporal`, `spectral`, `fractal` or `all`.",
+            )
+        elif isinstance(domain, list) and not np.all([d in valid_domains for d in domain]):
+            raise ValueError(
+                "At least one invalid domain was provided. Please choose from `statistical`, `temporal`, `spectral`, `fractal` or `all`.",
+            )
+        elif not isinstance(domain, (str, list)) and domain is not None:
+            raise TypeError(
+                "The 'domain' argument must be a string or a list of strings.",
             )
 
     dict_features = load_json(json_path)
     if domain is None:
         return dict_features
     else:
-        if domain == "fractal":
-            for k in dict_features[domain]:
-                dict_features[domain][k]["use"] = "yes"
-        return {domain: dict_features[domain]}
+        if domain == "all":
+            domain = ["statistical", "temporal", "spectral", "fractal"]
+
+        if isinstance(domain, str):
+            domain = [domain]
+
+        d_feat = {}
+        for d in domain:
+            if d == "fractal":
+                for k in dict_features[d]:
+                    dict_features[d][k]["use"] = "yes"
+            d_feat.update({d: dict_features[d]})
+        return d_feat           
 
 
 def get_features_by_tag(tag=None, json_path=None):