diff --git a/esphome/components/modbus/modbus.cpp b/esphome/components/modbus/modbus.cpp
index 4d75675d0..897a2895e 100644
--- a/esphome/components/modbus/modbus.cpp
+++ b/esphome/components/modbus/modbus.cpp
@@ -47,7 +47,7 @@ bool Modbus::parse_modbus_byte_(uint8_t byte) {
   uint8_t function_code = raw[1];
   // Byte 2: Size (with modbus rtu function code 4/3)
   // See also https://en.wikipedia.org/wiki/Modbus
-  if (at == 2)
+  if (at <= 2)
     return true;
 
   uint8_t data_len = raw[2];