diff --git a/homeassistant/components/modbus/__init__.py b/homeassistant/components/modbus/__init__.py
index 4ccf8d607ca..2ebab4635b3 100644
--- a/homeassistant/components/modbus/__init__.py
+++ b/homeassistant/components/modbus/__init__.py
@@ -183,19 +183,21 @@ SWITCH_SCHEMA = BASE_COMPONENT_SCHEMA.extend(
         ),
         vol.Optional(CONF_COMMAND_OFF, default=0x00): cv.positive_int,
         vol.Optional(CONF_COMMAND_ON, default=0x01): cv.positive_int,
-        vol.Optional(CONF_VERIFY): {
-            vol.Optional(CONF_ADDRESS): cv.positive_int,
-            vol.Optional(CONF_INPUT_TYPE): vol.In(
-                [
-                    CALL_TYPE_REGISTER_HOLDING,
-                    CALL_TYPE_DISCRETE,
-                    CALL_TYPE_REGISTER_INPUT,
-                    CALL_TYPE_COIL,
-                ]
-            ),
-            vol.Optional(CONF_STATE_OFF): cv.positive_int,
-            vol.Optional(CONF_STATE_ON): cv.positive_int,
-        },
+        vol.Optional(CONF_VERIFY): vol.Maybe(
+            {
+                vol.Optional(CONF_ADDRESS): cv.positive_int,
+                vol.Optional(CONF_INPUT_TYPE): vol.In(
+                    [
+                        CALL_TYPE_REGISTER_HOLDING,
+                        CALL_TYPE_DISCRETE,
+                        CALL_TYPE_REGISTER_INPUT,
+                        CALL_TYPE_COIL,
+                    ]
+                ),
+                vol.Optional(CONF_STATE_OFF): cv.positive_int,
+                vol.Optional(CONF_STATE_ON): cv.positive_int,
+            }
+        ),
     }
 )
 
diff --git a/homeassistant/components/modbus/switch.py b/homeassistant/components/modbus/switch.py
index 6fff8c1d373..c449c25bb22 100644
--- a/homeassistant/components/modbus/switch.py
+++ b/homeassistant/components/modbus/switch.py
@@ -70,6 +70,8 @@ class ModbusSwitch(SwitchEntity, RestoreEntity):
             self._command_on = config[CONF_COMMAND_ON]
             self._command_off = config[CONF_COMMAND_OFF]
         if CONF_VERIFY in config:
+            if config[CONF_VERIFY] is None:
+                config[CONF_VERIFY] = {}
             self._verify_active = True
             self._verify_address = config[CONF_VERIFY].get(
                 CONF_ADDRESS, config[CONF_ADDRESS]
@@ -97,10 +99,9 @@ class ModbusSwitch(SwitchEntity, RestoreEntity):
         if state:
             self._is_on = state.state == STATE_ON
 
-        if self._verify_active:
-            async_track_time_interval(
-                self.hass, lambda arg: self.update(), self._scan_interval
-            )
+        async_track_time_interval(
+            self.hass, lambda arg: self.update(), self._scan_interval
+        )
 
     @property
     def is_on(self):
@@ -154,6 +155,8 @@ class ModbusSwitch(SwitchEntity, RestoreEntity):
     def update(self):
         """Update the entity state."""
         if not self._verify_active:
+            self._available = True
+            self.schedule_update_ha_state()
             return
 
         result = self._read_func(self._slave, self._verify_address, 1)