diff --git a/library/psa_crypto_pake.c b/library/psa_crypto_pake.c
index 7f730e5..05d5854 100644
--- a/library/psa_crypto_pake.c
+++ b/library/psa_crypto_pake.c
@@ -300,7 +300,7 @@
     if( ret != 0 )
         return( mbedtls_to_psa_error( ret ) );
 
-    operation->buffer = mbedtls_calloc( 1, 512 );
+    operation->buffer = mbedtls_calloc( 1, PSA_PAKE_BUFFER_SIZE );
     if( operation->buffer == NULL )
         return( PSA_ERROR_INSUFFICIENT_MEMORY );