diff --git a/library/bignum.c b/library/bignum.c
index 15cbf73..4b291d7 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -109,7 +109,7 @@
     if( X->n < nblimbs )
     {
         if( ( p = mbedtls_calloc( nblimbs, ciL ) ) == NULL )
-            return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
+            return( MBEDTLS_ERR_MPI_ALLOC_FAILED ); // LCOV_EXCL_LINE
 
         if( X->p != NULL )
         {
@@ -147,7 +147,7 @@
         i = nblimbs;
 
     if( ( p = mbedtls_calloc( i, ciL ) ) == NULL )
-        return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
+        return( MBEDTLS_ERR_MPI_ALLOC_FAILED ); // LCOV_EXCL_LINE
 
     if( X->p != NULL )
     {
@@ -619,7 +619,7 @@
     {
         if( fwrite( p, 1, plen, fout ) != plen ||
             fwrite( s, 1, slen, fout ) != slen )
-            return( MBEDTLS_ERR_MPI_FILE_IO_ERROR );
+            return( MBEDTLS_ERR_MPI_FILE_IO_ERROR ); // LCOV_EXCL_LINE
     }
     else
         mbedtls_printf( "%s%s", p, s );
@@ -2232,13 +2232,13 @@
         mbedtls_printf( "  MPI test #1 (mul_mpi): " );
 
     if( mbedtls_mpi_cmp_mpi( &X, &U ) != 0 )
-    {
+    { // LCOV_EXCL_START
         if( verbose != 0 )
             mbedtls_printf( "failed\n" );
 
         ret = 1;
         goto cleanup;
-    }
+    } // LCOV_EXCL_STOP
 
     if( verbose != 0 )
         mbedtls_printf( "passed\n" );
@@ -2258,13 +2258,13 @@
 
     if( mbedtls_mpi_cmp_mpi( &X, &U ) != 0 ||
         mbedtls_mpi_cmp_mpi( &Y, &V ) != 0 )
-    {
+    { // LCOV_EXCL_START
         if( verbose != 0 )
             mbedtls_printf( "failed\n" );
 
         ret = 1;
         goto cleanup;
-    }
+    } // LCOV_EXCL_STOP
 
     if( verbose != 0 )
         mbedtls_printf( "passed\n" );
@@ -2280,13 +2280,13 @@
         mbedtls_printf( "  MPI test #3 (exp_mod): " );
 
     if( mbedtls_mpi_cmp_mpi( &X, &U ) != 0 )
-    {
+    { // LCOV_EXCL_START
         if( verbose != 0 )
             mbedtls_printf( "failed\n" );
 
         ret = 1;
         goto cleanup;
-    }
+    } // LCOV_EXCL_STOP
 
     if( verbose != 0 )
         mbedtls_printf( "passed\n" );
@@ -2302,13 +2302,13 @@
         mbedtls_printf( "  MPI test #4 (inv_mod): " );
 
     if( mbedtls_mpi_cmp_mpi( &X, &U ) != 0 )
-    {
+    { // LCOV_EXCL_START
         if( verbose != 0 )
             mbedtls_printf( "failed\n" );
 
         ret = 1;
         goto cleanup;
-    }
+    } // LCOV_EXCL_STOP
 
     if( verbose != 0 )
         mbedtls_printf( "passed\n" );
@@ -2324,13 +2324,13 @@
         MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &A, &X, &Y ) );
 
         if( mbedtls_mpi_cmp_int( &A, gcd_pairs[i][2] ) != 0 )
-        {
+        { // LCOV_EXCL_START
             if( verbose != 0 )
                 mbedtls_printf( "failed at %d\n", i );
 
             ret = 1;
             goto cleanup;
-        }
+        } // LCOV_EXCL_STOP
     }
 
     if( verbose != 0 )
@@ -2339,7 +2339,7 @@
 cleanup:
 
     if( ret != 0 && verbose != 0 )
-        mbedtls_printf( "Unexpected error, return code = %08X\n", ret );
+        mbedtls_printf( "Unexpected error, return code = %08X\n", ret ); // LCOV_EXCL_LINE
 
     mbedtls_mpi_free( &A ); mbedtls_mpi_free( &E ); mbedtls_mpi_free( &N ); mbedtls_mpi_free( &X );
     mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &U ); mbedtls_mpi_free( &V );