diff --git a/tests/suites/test_suite_mpi.function b/tests/suites/test_suite_mpi.function
index 3278eb1..2dacde8 100644
--- a/tests/suites/test_suite_mpi.function
+++ b/tests/suites/test_suite_mpi.function
@@ -455,7 +455,7 @@
 {
     mpi X;
     int res;
-    t_int r;
+    t_uint r;
     mpi_init(&X, NULL);
 
     TEST_ASSERT( mpi_read_string( &X, {radix_X}, {input_X} ) == 0 );