diff --git a/include/cryb/mpi.h b/include/cryb/mpi.h
index 8020a09..e9553e4 100644
--- a/include/cryb/mpi.h
+++ b/include/cryb/mpi.h
@@ -53,5 +53,7 @@ int mpi_lshift(cryb_mpi *, unsigned int);
 int mpi_rshift(cryb_mpi *, unsigned int);
 int mpi_add_abs(cryb_mpi *, cryb_mpi *, cryb_mpi *);
 int mpi_sub_abs(cryb_mpi *, cryb_mpi *, cryb_mpi *);
+int mpi_cmp_abs(cryb_mpi *, cryb_mpi *);
+int mpi_cmp(cryb_mpi *, cryb_mpi *);
 
 #endif
diff --git a/t/t_mpi.c b/t/t_mpi.c
index 27f06f1..e818a5d 100644
--- a/t/t_mpi.c
+++ b/t/t_mpi.c
@@ -586,6 +586,12 @@ static struct t_cmp_case {
 	size_t blen;
 	int cmpabs, cmp;
 } t_cmp_cases[] = {
+	{
+		"0 == 0",
+		{ 0x00, }, 1,
+		{ 0x00, }, 1,
+		0, 0,
+	},
 };
 
 static int
@@ -597,8 +603,8 @@ t_mpi_cmp(char **desc CRYB_UNUSED, void *arg)
 
 	mpi_load(&a, tc->a, tc->alen);
 	mpi_load(&b, tc->b, tc->blen);
-	ret &= t_compare_int(tc->cmpabs, mpi_cmp_abs(&a, &b));
-	ret &= t_compare_int(tc->cmp, mpi_cmp(&a, &b));
+	ret &= t_compare_i(tc->cmpabs, mpi_cmp_abs(&a, &b));
+	ret &= t_compare_i(tc->cmp, mpi_cmp(&a, &b));
 	mpi_destroy(&a);
 	mpi_destroy(&b);
 	return (ret);