diff --git a/library/bignum_core.h b/library/bignum_core.h
index cb932388e..d8951486c 100644
--- a/library/bignum_core.h
+++ b/library/bignum_core.h
@@ -101,7 +101,7 @@ void mbedtls_mpi_core_cond_assign( mbedtls_mpi_uint *X,
                                    unsigned char assign );
 
 /**
- * \brief   Perform a safe conditional copy of MPI which doesn't reveal whether
+ * \brief   Perform a safe conditional swap of MPI which doesn't reveal whether
  *          the condition was true or not.
  *
  * \param[IN,OUT] X         The address of the first MPI.
diff --git a/library/bignum_mod_raw.h b/library/bignum_mod_raw.h
index bdd2eada9..82a8ce851 100644
--- a/library/bignum_mod_raw.h
+++ b/library/bignum_mod_raw.h
@@ -58,7 +58,7 @@ void mbedtls_mpi_mod_raw_cond_assign( mbedtls_mpi_uint *X,
                                       unsigned char assign );
 
 /**
- * \brief   Perform a safe conditional copy of MPI which doesn't reveal whether
+ * \brief   Perform a safe conditional swap of MPI which doesn't reveal whether
  *          the condition was true or not.
  *
  * \param[IN,OUT] X     The address of the first MPI. This must be initialized.