diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 3c2b6a07ba..d4a8307574 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -6940,7 +6940,7 @@ static psa_status_t psa_key_agreement_internal(psa_key_derivation_operation_t *o
                                                size_t peer_key_length)
 {
     psa_status_t status;
-    uint8_t shared_secret[PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE];
+    uint8_t shared_secret[PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE] = { 0 };
     size_t shared_secret_length = 0;
     psa_algorithm_t ka_alg = PSA_ALG_KEY_AGREEMENT_GET_BASE(operation->alg);