diff --git a/src/db/unit_tests/dbPLCConvexDecompositionTests.cc b/src/db/unit_tests/dbPLCConvexDecompositionTests.cc
index 6b57ef505..007e6d4d6 100644
--- a/src/db/unit_tests/dbPLCConvexDecompositionTests.cc
+++ b/src/db/unit_tests/dbPLCConvexDecompositionTests.cc
@@ -145,7 +145,7 @@ TEST(internal_vertex)
 
   std::vector<std::string> ip;
   for (size_t i = 0; i < p->internal_vertexes (); ++i) {
-    ip.push_back (p->internal_vertex (i)->to_string () + "#" + tl::to_string (p->internal_vertex (i)->ids ()));
+    ip.push_back (p->internal_vertex (i)->to_string () + "#" + tl::join (p->internal_vertex (i)->ids ().begin (), p->internal_vertex (i)->ids ().end (), ","));
   }
   std::sort (ip.begin (), ip.end ());
   EXPECT_EQ (tl::join (ip, "/"), "(0, 0)#2/(0, 0.05)#0/(0.2, 0.07)#1");
diff --git a/src/db/unit_tests/dbPLCGraphTests.cc b/src/db/unit_tests/dbPLCGraphTests.cc
index 9a907a1c6..1e91948f3 100644
--- a/src/db/unit_tests/dbPLCGraphTests.cc
+++ b/src/db/unit_tests/dbPLCGraphTests.cc
@@ -61,7 +61,7 @@ TEST(basic)
   v1->set_is_precious (true, 1);
   EXPECT_EQ (v1->is_precious (), true);
   EXPECT_EQ (v1->ids ().size (), 2u);
-  EXPECT_EQ (*v1->ids ().begin (), 2u);
+  EXPECT_EQ (*v1->ids ().begin (), 1u);
 }
 
 TEST(edge)