diff --git a/tests/components/modbus/conftest.py b/tests/components/modbus/conftest.py
index 460b1eb5dd3..d7e4556f746 100644
--- a/tests/components/modbus/conftest.py
+++ b/tests/components/modbus/conftest.py
@@ -136,7 +136,7 @@ async def mock_pymodbus_exception_fixture(hass, do_exception, mock_modbus):
 @pytest.fixture(name="mock_pymodbus_return")
 async def mock_pymodbus_return_fixture(hass, register_words, mock_modbus):
     """Trigger update call with time_changed event."""
-    read_result = ReadResult(register_words)
+    read_result = ReadResult(register_words) if register_words else None
     mock_modbus.read_coils.return_value = read_result
     mock_modbus.read_discrete_inputs.return_value = read_result
     mock_modbus.read_input_registers.return_value = read_result
diff --git a/tests/components/modbus/test_init.py b/tests/components/modbus/test_init.py
index f9c7fb42b2d..5f8c0554e6d 100644
--- a/tests/components/modbus/test_init.py
+++ b/tests/components/modbus/test_init.py
@@ -40,6 +40,7 @@ from homeassistant.components.modbus.const import (
     CALL_TYPE_WRITE_REGISTERS,
     CONF_BAUDRATE,
     CONF_BYTESIZE,
+    CONF_CLOSE_COMM_ON_ERROR,
     CONF_DATA_TYPE,
     CONF_DEVICE_ADDRESS,
     CONF_INPUT_TYPE,
@@ -413,6 +414,12 @@ async def test_duplicate_entity_validator(do_config) -> None:
 @pytest.mark.parametrize(
     "do_config",
     [
+        {
+            CONF_TYPE: TCP,
+            CONF_HOST: TEST_MODBUS_HOST,
+            CONF_PORT: TEST_PORT_TCP,
+            CONF_CLOSE_COMM_ON_ERROR: True,
+        },
         {
             CONF_TYPE: TCP,
             CONF_HOST: TEST_MODBUS_HOST,
diff --git a/tests/components/modbus/test_sensor.py b/tests/components/modbus/test_sensor.py
index 46c38873a93..0f79a125c86 100644
--- a/tests/components/modbus/test_sensor.py
+++ b/tests/components/modbus/test_sensor.py
@@ -409,6 +409,17 @@ async def test_config_wrong_struct_sensor(
             False,
             "-1985229329",
         ),
+        (
+            {
+                CONF_DATA_TYPE: DataType.INT32,
+                CONF_SCALE: 1,
+                CONF_OFFSET: 0,
+                CONF_PRECISION: 0,
+            },
+            [0x89AB],
+            False,
+            STATE_UNAVAILABLE,
+        ),
         (
             {
                 CONF_DATA_TYPE: DataType.UINT32,
@@ -751,6 +762,15 @@ async def test_all_sensor(hass: HomeAssistant, mock_do_cycle, expected) -> None:
             False,
             ["16909060", "67305985"],
         ),
+        (
+            {
+                CONF_VIRTUAL_COUNT: 2,
+                CONF_UNIQUE_ID: SLAVE_UNIQUE_ID,
+            },
+            [0x0102, 0x0304, 0x0403, 0x0201, 0x0403],
+            False,
+            [STATE_UNAVAILABLE, STATE_UNKNOWN, STATE_UNKNOWN],
+        ),
         (
             {
                 CONF_SLAVE_COUNT: 3,