diff --git a/.github/workflows/compliance.yml b/.github/workflows/compliance.yml
index f2b7b78..7d8599d 100644
--- a/.github/workflows/compliance.yml
+++ b/.github/workflows/compliance.yml
@@ -27,10 +27,7 @@ jobs:
       - name: Install python dependencies
         working-directory: enki
         run: |
-          pip install -r requirements.txt
-          pip install pylint
-          pip install pylint-protobuf
-
+          pip install -r requirements_pylint.txt
       - name: Running pylint
         working-directory: enki
         run: |
diff --git a/requirements_pylint.txt b/requirements_pylint.txt
new file mode 100644
index 0000000..eba2826
--- /dev/null
+++ b/requirements_pylint.txt
@@ -0,0 +1,4 @@
+-r requirements.txt
+
+pylint==2.17.5
+pylint-protobuf==0.20.2
diff --git a/shell.py b/shell.py
index 00bac04..fc26878 100644
--- a/shell.py
+++ b/shell.py
@@ -5,7 +5,7 @@
 import cmd2
 
 import sparkplug_b_pb2
-from sparkplug_b import MetricDataType, addMetric, initDatasetMetric
+from sparkplug_b import MetricDataType, addMetric, addNullMetric, initDatasetMetric
 
 import sp_helpers
 from sp_helpers import MsgType
@@ -24,6 +24,20 @@ def str_to_int(string):
         return int(string, 16)
     return int(string)
 
+
+def str_to_bool(string):
+    """Convert a user string to a bool value
+
+    Accepted values for True are: True, Yes, Y, 1
+    The string is case-insensitive
+    All other values are considered equal to False
+    """
+    string = string.lower()
+    if string in ["true", "yes", "y", "1"]:
+        return True
+    return False
+
+
 def get_bytearray_str(bytes_array):
     """String representation of a bytearray value."""
     size = len(bytes_array)
@@ -277,15 +291,17 @@ def query_yes_no(self, prompt):
     def prompt_user_simple_datatype(self, name, datatype):
         """Ask the user to give a value for simple datatypes."""
         prompt = f"[{sp_helpers.datatype_to_str(datatype)}] {name}: "
+        value = None
+        try:
+            usr_input = self.read_input(prompt)
+        except EOFError:
+            return None
         if datatype in sp_helpers.boolean_value_types:
-            usr_input = self.select([(True, "True"),
-                                     (False, "False")], prompt)
-            value = usr_input
+            value = str_to_bool(usr_input)
         elif datatype in sp_helpers.int_value_types + sp_helpers.long_value_types:
-            usr_input = self.read_input(prompt)
             value = str_to_int(usr_input)
         elif datatype in sp_helpers.string_value_types:
-            value = self.read_input(prompt)
+            value = usr_input
         return value
 
     def forge_dataset_metric(self, payload, metric):
@@ -301,7 +317,10 @@ def forge_dataset_metric(self, payload, metric):
                 name = f"{metric.name}/{col}"
                 value = self.prompt_user_simple_datatype(name, datatype)
                 element = row.elements.add()
-                sp_helpers.set_typed_value(datatype, element, value)
+                if value is not None:
+                    sp_helpers.set_typed_value(datatype, element, value)
+                else:
+                    element.is_null = True
             new_row = self.query_yes_no("new row ?")
 
     def forge_payload_from_metric(self, payload, metric):
@@ -312,8 +331,11 @@ def forge_payload_from_metric(self, payload, metric):
         if metric.datatype in simple_datatypes:
             value = self.prompt_user_simple_datatype(metric.name,
                                                      metric.datatype)
-            addMetric(payload, metric.name, metric.alias, metric.datatype,
-                      value)
+            if value is not None:
+                addMetric(payload, metric.name, metric.alias, metric.datatype,
+                          value)
+            else:
+                addNullMetric(payload, metric.name, metric.alias, metric.datatype)
         elif metric.datatype == MetricDataType.DataSet:
             self.forge_dataset_metric(payload, metric)
         else: