diff --git a/library/bignum_mod_raw.c b/library/bignum_mod_raw.c
index 98994ab..3c7f889 100644
--- a/library/bignum_mod_raw.c
+++ b/library/bignum_mod_raw.c
@@ -46,8 +46,7 @@
                                       const mbedtls_mpi_mod_modulus *m,
                                       unsigned char assign )
 {
-    mbedtls_mpi_core_cond_assign( X, m->limbs,
-                                  Y, m->limbs, assign );
+    mbedtls_mpi_core_cond_assign( X, Y, m->limbs, assign );
 }
 
 void mbedtls_mpi_mod_raw_cond_swap( mbedtls_mpi_uint *X,