diff --git a/include/psa/crypto_builtin_cipher.h b/include/psa/crypto_builtin_cipher.h
index 0fd577a..df26c91 100644
--- a/include/psa/crypto_builtin_cipher.h
+++ b/include/psa/crypto_builtin_cipher.h
@@ -39,8 +39,8 @@
 typedef struct {
     /* Context structure for the Mbed TLS cipher implementation. */
     psa_algorithm_t alg;
-    uint8_t iv_size;
-    uint8_t block_size;
+    uint8_t iv_length;
+    uint8_t block_length;
     mbedtls_cipher_context_t cipher;
 } mbedtls_psa_cipher_operation_t;
 
diff --git a/library/psa_crypto_cipher.c b/library/psa_crypto_cipher.c
index dac9d7f..464bd57 100644
--- a/library/psa_crypto_cipher.c
+++ b/library/psa_crypto_cipher.c
@@ -219,18 +219,18 @@
         goto exit;
 #endif /* BUILTIN_ALG_CBC_NO_PADDING || BUILTIN_ALG_CBC_PKCS7 */
 
-    operation->block_size = ( PSA_ALG_IS_STREAM_CIPHER( alg ) ? 1 :
-                              PSA_BLOCK_CIPHER_BLOCK_LENGTH( key_type ) );
+    operation->block_length = ( PSA_ALG_IS_STREAM_CIPHER( alg ) ? 1 :
+                                PSA_BLOCK_CIPHER_BLOCK_LENGTH( key_type ) );
     if( ( alg & PSA_ALG_CIPHER_FROM_BLOCK_FLAG ) != 0 &&
         alg != PSA_ALG_ECB_NO_PADDING )
     {
-        operation->iv_size = PSA_BLOCK_CIPHER_BLOCK_LENGTH( key_type );
+        operation->iv_length = PSA_BLOCK_CIPHER_BLOCK_LENGTH( key_type );
     }
 #if defined(BUILTIN_KEY_TYPE_CHACHA20)
     else
     if( ( alg == PSA_ALG_STREAM_CIPHER ) &&
         ( key_type == PSA_KEY_TYPE_CHACHA20 ) )
-        operation->iv_size = 12;
+        operation->iv_length = 12;
 #endif
 
 exit:
@@ -262,7 +262,7 @@
 static psa_status_t cipher_set_iv( mbedtls_psa_cipher_operation_t *operation,
                             const uint8_t *iv, size_t iv_length )
 {
-    if( iv_length != operation->iv_size )
+    if( iv_length != operation->iv_length )
         return( PSA_ERROR_INVALID_ARGUMENT );
 
     return( mbedtls_to_psa_error(
@@ -276,14 +276,14 @@
 {
     int status = PSA_ERROR_CORRUPTION_DETECTED;
 
-    if( iv_size < operation->iv_size )
+    if( iv_size < operation->iv_length )
         return( PSA_ERROR_BUFFER_TOO_SMALL );
 
-    status = psa_generate_random( iv, operation->iv_size );
+    status = psa_generate_random( iv, operation->iv_length );
     if( status != PSA_SUCCESS )
         return( status );
 
-    *iv_length = operation->iv_size;
+    *iv_length = operation->iv_length;
 
     return( cipher_set_iv( operation, iv, *iv_length ) );
 }
@@ -394,7 +394,7 @@
          * output in this call. */
         expected_output_size =
             ( operation->cipher.unprocessed_len + input_length )
-            / operation->block_size * operation->block_size;
+            / operation->block_length * operation->block_length;
     }
     else
     {