diff --git a/homeassistant/components/modbus/__init__.py b/homeassistant/components/modbus/__init__.py
index 0f674d4d0df49e..36e841f7859745 100644
--- a/homeassistant/components/modbus/__init__.py
+++ b/homeassistant/components/modbus/__init__.py
@@ -186,7 +186,7 @@
             ]
         ),
         vol.Optional(CONF_STRUCTURE): cv.string,
-        vol.Optional(CONF_SCALE, default=1): cv.positive_float,
+        vol.Optional(CONF_SCALE, default=1): vol.Coerce(float),
         vol.Optional(CONF_OFFSET, default=0): vol.Coerce(float),
         vol.Optional(CONF_PRECISION): cv.positive_int,
         vol.Optional(
diff --git a/tests/components/modbus/test_sensor.py b/tests/components/modbus/test_sensor.py
index 97571041482e41..5ca38873c423c7 100644
--- a/tests/components/modbus/test_sensor.py
+++ b/tests/components/modbus/test_sensor.py
@@ -688,6 +688,16 @@ async def test_config_wrong_struct_sensor(
             False,
             "112594",
         ),
+        (
+            {
+                CONF_DATA_TYPE: DataType.INT16,
+                CONF_SCALE: -1,
+                CONF_OFFSET: 0,
+            },
+            [0x000A],
+            False,
+            "-10",
+        ),
     ],
 )
 async def test_all_sensor(hass: HomeAssistant, mock_do_cycle, expected) -> None: