diff --git a/esphome/core/helpers.cpp b/esphome/core/helpers.cpp
index dee771d4e9..7f040f855f 100644
--- a/esphome/core/helpers.cpp
+++ b/esphome/core/helpers.cpp
@@ -93,7 +93,7 @@ std::string to_string(long double value) { return str_snprintf("%Lf", 32, value)
 // Mathematics
 
 float lerp(float completion, float start, float end) { return start + (end - start) * completion; }
-uint8_t crc8(uint8_t *data, uint8_t len) {
+uint8_t crc8(const uint8_t *data, uint8_t len) {
   uint8_t crc = 0;
 
   while ((len--) != 0u) {
diff --git a/esphome/core/helpers.h b/esphome/core/helpers.h
index 4af840f77b..b4ad22b083 100644
--- a/esphome/core/helpers.h
+++ b/esphome/core/helpers.h
@@ -155,7 +155,7 @@ template<typename T, typename U> T remap(U value, U min, U max, T min_out, T max
 }
 
 /// Calculate a CRC-8 checksum of \p data with size \p len.
-uint8_t crc8(uint8_t *data, uint8_t len);
+uint8_t crc8(const uint8_t *data, uint8_t len);
 
 /// Calculate a CRC-16 checksum of \p data with size \p len.
 uint16_t crc16(const uint8_t *data, uint16_t len, uint16_t crc = 0xffff, uint16_t reverse_poly = 0xa001,