diff --git a/tests/mgcp/mgcp_test.c b/tests/mgcp/mgcp_test.c
index 7397f5c..bcbcc02 100644
--- a/tests/mgcp/mgcp_test.c
+++ b/tests/mgcp/mgcp_test.c
@@ -2149,42 +2149,50 @@
 
 void test_e1_trunk_nr_from_epname()
 {
-	int trunk_nr;
+	unsigned int trunk_nr;
+	int rc;
 
 	/* Note: e1_trunk_nr_from_epname does not check the text
 	 * after the E1 trunk number, after the delimiter
 	 * character "/" arbitrary text may follow. */
-	trunk_nr = e1_trunk_nr_from_epname("ds/e1-0/s-1/su16-0");
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "ds/e1-0/s-1/su16-0");
 	OSMO_ASSERT(trunk_nr == 0);
-	trunk_nr = e1_trunk_nr_from_epname("ds/e1-1/s-1/su16-0");
+	OSMO_ASSERT(rc == 0);
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "ds/e1-1/s-1/su16-0");
 	OSMO_ASSERT(trunk_nr == 1);
-	trunk_nr = e1_trunk_nr_from_epname("ds/e1-2/s-2/su16-0");
+	OSMO_ASSERT(rc == 0);
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "ds/e1-2/s-2/su16-0");
 	OSMO_ASSERT(trunk_nr == 2);
-	trunk_nr = e1_trunk_nr_from_epname("ds/e1-3/s-23/su32-0");
+	OSMO_ASSERT(rc == 0);
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "ds/e1-3/s-23/su32-0");
 	OSMO_ASSERT(trunk_nr == 3);
-	trunk_nr = e1_trunk_nr_from_epname("ds/e1-3/xxxxxxx");
+	OSMO_ASSERT(rc == 0);
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "ds/e1-3/xxxxxxx");
 	OSMO_ASSERT(trunk_nr == 3);
-	trunk_nr = e1_trunk_nr_from_epname("ds/e1-24/s-1/su16-0");
+	OSMO_ASSERT(rc == 0);
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "ds/e1-24/s-1/su16-0");
 	OSMO_ASSERT(trunk_nr == 24);
-	trunk_nr = e1_trunk_nr_from_epname("ds/e1-64/s-1/su16-0");
+	OSMO_ASSERT(rc == 0);
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "ds/e1-64/s-1/su16-0");
 	OSMO_ASSERT(trunk_nr == 64);
+	OSMO_ASSERT(rc == 0);
 
 	/* The following endpoint strings should fail, either the
 	 * trunk number exceeds the valid range or the trunk prefix
 	 * is wrong. Also when the delimiter character "/" at the
 	 * end of the trunk is wrong the parsing should fail. */
-	trunk_nr = e1_trunk_nr_from_epname("ds/e1-65/s-1/su16-0");
-	OSMO_ASSERT(trunk_nr == -EINVAL);
-	trunk_nr = e1_trunk_nr_from_epname("ds/e1--1/s-1/su16-0");
-	OSMO_ASSERT(trunk_nr == -EINVAL);
-	trunk_nr = e1_trunk_nr_from_epname("xxxxxx4zyz");
-	OSMO_ASSERT(trunk_nr == -EINVAL);
-	trunk_nr = e1_trunk_nr_from_epname("ds/e1+2/s-1/su16-0");
-	OSMO_ASSERT(trunk_nr == -EINVAL);
-	trunk_nr = e1_trunk_nr_from_epname("ds/e2-24/s-1/su16-0");
-	OSMO_ASSERT(trunk_nr == -EINVAL);
-	trunk_nr = e1_trunk_nr_from_epname("ds/e1-24s-1/su16-0");
-	OSMO_ASSERT(trunk_nr == -EINVAL);
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "ds/e1-65/s-1/su16-0");
+	OSMO_ASSERT(rc == -EINVAL);
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "ds/e1--1/s-1/su16-0");
+	OSMO_ASSERT(rc == -EINVAL);
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "xxxxxx4zyz");
+	OSMO_ASSERT(rc == -EINVAL);
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "ds/e1+2/s-1/su16-0");
+	OSMO_ASSERT(rc == -EINVAL);
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "ds/e2-24/s-1/su16-0");
+	OSMO_ASSERT(rc == -EINVAL);
+	rc = e1_trunk_nr_from_epname(&trunk_nr, "ds/e1-24s-1/su16-0");
+	OSMO_ASSERT(rc == -EINVAL);
 
 	return;
 }