diff --git a/tests/gtp/gtpie_test.c b/tests/gtp/gtpie_test.c
index fe2d502..8d87dcc 100644
--- a/tests/gtp/gtpie_test.c
+++ b/tests/gtp/gtpie_test.c
@@ -124,4 +124,5 @@
 	/* TODO: gtpie_encaps() */
 	/* TODO: gtpie_encaps2() */
 	/* TODO: gtpie_getie(), gtpie_exist(), gtpie_get*() */
+	return 0;
 }
diff --git a/tests/lib/in46a_test.c b/tests/lib/in46a_test.c
index 42a1768..ab7156f 100644
--- a/tests/lib/in46a_test.c
+++ b/tests/lib/in46a_test.c
@@ -321,4 +321,5 @@
 	test_in46a_to_eua();
 	test_in46a_from_eua();
 	test_in46a_netmasklen();
+	return 0;
 }
diff --git a/tests/lib/ippool_test.c b/tests/lib/ippool_test.c
index ea56edd..5b3227c 100644
--- a/tests/lib/ippool_test.c
+++ b/tests/lib/ippool_test.c
@@ -130,4 +130,5 @@
 	srand(time(NULL));
 
 	test_pool_sizes();
+	return 0;
 }