diff --git a/firebase_admin/remote_config.py b/firebase_admin/remote_config.py
index 880804d3..d848899b 100644
--- a/firebase_admin/remote_config.py
+++ b/firebase_admin/remote_config.py
@@ -487,10 +487,10 @@ def evaluate_custom_signal_condition(self, custom_signal_condition,
         Returns:
           True if the condition is met, False otherwise.
         """
-        custom_signal_operator = custom_signal_condition.get('customSignalOperator') or {}
-        custom_signal_key = custom_signal_condition.get('customSignalKey') or {}
+        custom_signal_operator = custom_signal_condition.get('customSignalOperator') or ''
+        custom_signal_key = custom_signal_condition.get('customSignalKey') or ''
         target_custom_signal_values = (
-            custom_signal_condition.get('targetCustomSignalValues') or {})
+            custom_signal_condition.get('targetCustomSignalValues') or [])
 
         if not all([custom_signal_operator, custom_signal_key, target_custom_signal_values]):
             logger.warning("Missing operator, key, or target values for custom signal condition.")
@@ -498,9 +498,10 @@ def evaluate_custom_signal_condition(self, custom_signal_condition,
 
         if not target_custom_signal_values:
             return False
-        actual_custom_signal_value = context.get(custom_signal_key) or {}
+        actual_custom_signal_value = context.get(custom_signal_key)
 
-        if not actual_custom_signal_value:
+        # Falsy signal values such as 0 are valid; only a missing signal is skipped.
+        if actual_custom_signal_value is None:
             logger.debug("Custom signal value not found in context: %s", custom_signal_key)
             return False
 
@@ -613,7 +614,7 @@ def _compare_numbers(self, custom_signal_key, target_value, actual_value, predic
             actual = float(actual_value)
             result = -1 if actual < target else 1 if actual > target else 0
             return predicate_fn(result)
-        except ValueError:
+        except (ValueError, TypeError):
             logger.warning("Invalid numeric value for comparison for custom signal key %s.",
                            custom_signal_key)
             return False
@@ -739,7 +740,7 @@ def as_boolean(self) -> bool:
             return self.DEFAULT_VALUE_FOR_BOOLEAN
         return str(self.value).lower() in self.BOOLEAN_TRUTHY_VALUES
 
-    def as_int(self) -> float:
+    def as_int(self) -> int:
         """Returns the value as a number."""
         if self.source == 'static':
             return self.DEFAULT_VALUE_FOR_INTEGER
diff --git a/tests/test_remote_config.py b/tests/test_remote_config.py
index 7bbf9721..c4cb4f19 100644
--- a/tests/test_remote_config.py
+++ b/tests/test_remote_config.py
@@ -820,6 +820,83 @@ def test_evaluate_custom_signal_semantic_version(self,
         assert server_config.get_boolean('is_enabled') == parameter_value
 
 
+    @pytest.mark.parametrize(
+        'custom_signal_operator, target_custom_signal_value, context_value, parameter_value',
+        [
+            (CustomSignalOperator.NUMERIC_EQUAL.value, ['0'], 0, True),
+            (CustomSignalOperator.NUMERIC_LESS_THAN.value, ['1'], 0, True),
+            (CustomSignalOperator.NUMERIC_GREATER_THAN.value, ['-1'], 0.0, True),
+            (CustomSignalOperator.NUMERIC_GREATER_THAN.value, ['0'], 0, False),
+            (CustomSignalOperator.STRING_EXACTLY_MATCHES.value, ['0'], 0, True),
+        ])
+    def test_evaluate_custom_signal_zero_value(self,
+                                               custom_signal_operator,
+                                               target_custom_signal_value,
+                                               context_value,
+                                               parameter_value):
+        server_template = self._custom_signal_template(custom_signal_operator,
+                                                       target_custom_signal_value)
+        context = {'randomization_id': '123', 'signal_key': context_value}
+        server_config = server_template.evaluate(context)
+        assert server_config.get_boolean('is_enabled') == parameter_value
+
+    @pytest.mark.parametrize('context_value', [[], {}])
+    @pytest.mark.parametrize('operator', [
+        CustomSignalOperator.NUMERIC_LESS_THAN,
+        CustomSignalOperator.NUMERIC_LESS_EQUAL,
+        CustomSignalOperator.NUMERIC_EQUAL,
+        CustomSignalOperator.NUMERIC_NOT_EQUAL,
+        CustomSignalOperator.NUMERIC_GREATER_THAN,
+        CustomSignalOperator.NUMERIC_GREATER_EQUAL,
+    ])
+    def test_evaluate_custom_signal_non_numeric_value(self, context_value, operator):
+        server_template = self._custom_signal_template(operator.value, ['0'])
+        server_config = server_template.evaluate({'signal_key': context_value})
+        assert server_config.get_boolean('is_enabled') is False
+
+    def test_evaluate_custom_signal_missing_value(self):
+        server_template = self._custom_signal_template(
+            CustomSignalOperator.NUMERIC_LESS_THAN.value, ['1'])
+        server_config = server_template.evaluate({'randomization_id': '123'})
+        assert server_config.get_boolean('is_enabled') is False
+
+    def _custom_signal_template(self, custom_signal_operator, target_custom_signal_value):
+        condition = {
+            'name': 'is_true',
+            'condition': {
+                'orCondition': {
+                    'conditions': [{
+                        'andCondition': {
+                            'conditions': [{
+                                'customSignal': {
+                                    'customSignalOperator': custom_signal_operator,
+                                    'customSignalKey': 'signal_key',
+                                    'targetCustomSignalValues': target_custom_signal_value
+                                }
+                            }],
+                        }
+                    }]
+                }
+            }
+        }
+        template_data = {
+            'conditions': [condition],
+            'parameters': {
+                'is_enabled': {
+                    'defaultValue': {'value': 'false'},
+                    'conditionalValues': {'is_true': {'value': 'true'}}
+                },
+            },
+            'parameterGroups': '',
+            'version': '',
+            'etag': '123'
+        }
+        return remote_config.init_server_template(
+            app=firebase_admin.get_app(),
+            default_config={'dog_is_cute': True},
+            template_data_json=json.dumps(template_data)
+        )
+
 class MockAdapter(testutils.MockAdapter):
     """A Mock HTTP Adapter that provides Firebase Remote Config responses with ETag in header."""