diff --git a/esphome/components/mhz19/mhz19.cpp b/esphome/components/mhz19/mhz19.cpp
index b5194dcc5e..cbac28f9c7 100644
--- a/esphome/components/mhz19/mhz19.cpp
+++ b/esphome/components/mhz19/mhz19.cpp
@@ -8,9 +8,9 @@ static const char *TAG = "mhz19";
 static const uint8_t MHZ19_REQUEST_LENGTH = 8;
 static const uint8_t MHZ19_RESPONSE_LENGTH = 9;
 static const uint8_t MHZ19_COMMAND_GET_PPM[] = {0xFF, 0x01, 0x86, 0x00, 0x00, 0x00, 0x00, 0x00};
-static const uint8_t MHZ19_COMMAND_ABC_ENABLE[] = {0xff, 0x01, 0x79, 0xA0, 0x00, 0x00, 0x00, 0x00};
-static const uint8_t MHZ19_COMMAND_ABC_DISABLE[] = {0xff, 0x01, 0x79, 0x00, 0x00, 0x00, 0x00, 0x00};
-static const uint8_t MHZ19_COMMAND_CALIBRATE_ZERO[] = {0xff, 0x01, 0x87, 0x00, 0x00, 0x00, 0x00, 0x00};
+static const uint8_t MHZ19_COMMAND_ABC_ENABLE[] = {0xFF, 0x01, 0x79, 0xA0, 0x00, 0x00, 0x00, 0x00};
+static const uint8_t MHZ19_COMMAND_ABC_DISABLE[] = {0xFF, 0x01, 0x79, 0x00, 0x00, 0x00, 0x00, 0x00};
+static const uint8_t MHZ19_COMMAND_CALIBRATE_ZERO[] = {0xFF, 0x01, 0x87, 0x00, 0x00, 0x00, 0x00, 0x00};
 
 uint8_t mhz19_checksum(const uint8_t *command) {
   uint8_t sum = 0;