diff --git a/library/cipher.c b/library/cipher.c
index 63f1f41..e854cf6 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -1236,7 +1236,7 @@
             (mbedtls_cipher_context_psa *) ctx->cipher_ctx;
 
         psa_status_t status;
-        psa_cipher_operation_t cipher_op;
+        psa_cipher_operation_t cipher_op = PSA_CIPHER_OPERATION_INIT;
         size_t part_len;
 
         if( ctx->operation == MBEDTLS_DECRYPT )
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index f224d5e..a0d2617 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -6529,7 +6529,7 @@
     unsigned char padbuf[32];
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     size_t hash_size;
-    psa_hash_operation_t sha256_psa;
+    psa_hash_operation_t sha256_psa = PSA_HASH_OPERATION_INIT;
     psa_status_t status;
 #else
     mbedtls_sha256_context sha256;
@@ -6605,7 +6605,7 @@
     unsigned char padbuf[48];
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     size_t hash_size;
-    psa_hash_operation_t sha384_psa;
+    psa_hash_operation_t sha384_psa = PSA_HASH_OPERATION_INIT;
     psa_status_t status;
 #else
     mbedtls_sha512_context sha512;
@@ -10203,7 +10203,7 @@
                                             mbedtls_md_type_t md_alg )
 {
     psa_status_t status;
-    psa_hash_operation_t hash_operation;
+    psa_hash_operation_t hash_operation = PSA_HASH_OPERATION_INIT;
     psa_algorithm_t hash_alg = mbedtls_psa_translate_md( md_alg );
 
     MBEDTLS_SSL_DEBUG_MSG( 1, ( "Perform PSA-based computation of digest of ServerKeyExchange" ) );
diff --git a/library/x509_crt.c b/library/x509_crt.c
index 1b1f0a7..1f853ba 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -1908,7 +1908,7 @@
     if( mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash ) != 0 )
         return( -1 );
 #else
-    psa_hash_operation_t hash_operation;
+    psa_hash_operation_t hash_operation = PSA_HASH_OPERATION_INIT;
     psa_algorithm_t hash_alg = mbedtls_psa_translate_md( child->sig_md );
 
     if( psa_hash_setup( &hash_operation, hash_alg ) != PSA_SUCCESS )
diff --git a/library/x509write_csr.c b/library/x509write_csr.c
index f2950ad..777a632 100644
--- a/library/x509write_csr.c
+++ b/library/x509write_csr.c
@@ -142,7 +142,7 @@
     size_t len = 0;
     mbedtls_pk_type_t pk_alg;
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
-    psa_hash_operation_t hash_operation;
+    psa_hash_operation_t hash_operation = PSA_HASH_OPERATION_INIT;
     size_t hash_len;
     psa_algorithm_t hash_alg = mbedtls_psa_translate_md( ctx->md_alg );
 #endif /* MBEDTLS_USE_PSA_CRYPTO */