diff --git a/include/psa/crypto_extra.h b/include/psa/crypto_extra.h
index 0ab5892..b2d4633 100644
--- a/include/psa/crypto_extra.h
+++ b/include/psa/crypto_extra.h
@@ -221,7 +221,7 @@
  *         The library has already been initialized. It is no longer
  *         possible to call this function.
  */
-psa_status_t mbedtls_psa_inject_entropy(const unsigned char *seed,
+psa_status_t mbedtls_psa_inject_entropy(uint8_t *seed,
                                         size_t seed_size);
 
 #if defined(PSA_PRE_1_0_KEY_DERIVATION)
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 08eff51..ff7654a 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -5313,7 +5313,7 @@
 #if defined(MBEDTLS_PSA_INJECT_ENTROPY)
 #include "mbedtls/entropy_poll.h"
 
-psa_status_t mbedtls_psa_inject_entropy( const unsigned char *seed,
+psa_status_t mbedtls_psa_inject_entropy( const uint8_t *seed,
                                          size_t seed_size )
 {
     if( global_data.initialized )