diff --git a/src/db/unit_tests/dbLayoutToNetlistTests.cc b/src/db/unit_tests/dbLayoutToNetlistTests.cc
index 53947ec0c..6b7f0fd8e 100644
--- a/src/db/unit_tests/dbLayoutToNetlistTests.cc
+++ b/src/db/unit_tests/dbLayoutToNetlistTests.cc
@@ -580,8 +580,7 @@ TEST(1_BasicExtraction)
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal2, db::DPoint (-2.0, 1.8))), "(null)");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (-1.5, 1.8))), "RINGO:FB");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (24.5, 1.8))), "RINGO:OSC");
-  //  the transistor which supplies this probe target has been optimized away by "purge".
-  EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (5.3, 0.0))), "(null)");
+  EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (5.3, 0.0))), "RINGO:VSS");
 
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (2.6, 1.0))), "RINGO:$I39");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (6.4, 1.0))), "RINGO:$I2");
@@ -831,8 +830,7 @@ TEST(2_Probing)
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal2, db::DPoint (-2.0, 1.8))), "(null)");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (-1.5, 1.8))), "RINGO:FB");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (24.5, 1.8))), "RINGO:OSC");
-  //  the transistor which supplies this probe target has been optimized away by "purge".
-  EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (5.3, 0.0))), "(null)");
+  EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (5.3, 0.0))), "RINGO:VSS");
 
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (2.6, 1.0))), "RINGO:$I18");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (6.4, 1.0))), "INV2PAIR:$I5");
@@ -1112,8 +1110,7 @@ TEST(3_GlobalNetConnections)
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal2, db::DPoint (-2.0, 1.8))), "(null)");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (-1.5, 1.8))), "RINGO:FB");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (24.5, 1.8))), "RINGO:OSC");
-  //  the transistor which supplies this probe target has been optimized away by "purge".
-  EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (5.3, 0.0))), "(null)");
+  EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (5.3, 0.0))), "RINGO:VSS");
 
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (2.6, 1.0))), "RINGO:$I22");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (6.4, 1.0))), "INV2PAIR:$I6");
@@ -1399,8 +1396,7 @@ TEST(4_GlobalNetDeviceExtraction)
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal2, db::DPoint (-2.0, 1.8))), "(null)");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (-1.5, 1.8))), "RINGO:FB");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (24.5, 1.8))), "RINGO:OSC");
-  //  the transistor which supplies this probe target has been optimized away by "purge".
-  EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (5.3, 0.0))), "(null)");
+  EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (5.3, 0.0))), "RINGO:VSS");
 
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (2.6, 1.0))), "RINGO:$I22");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (6.4, 1.0))), "INV2PAIR:$I6");
@@ -1681,8 +1677,7 @@ TEST(5_DeviceExtractionWithDeviceCombination)
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal2, db::DPoint (-2.0, 1.8))), "(null)");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (-1.5, 1.8))), "RINGO:FB");
   EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (24.5, 1.8))), "RINGO:OSC");
-  //  the transistor which supplies this probe target has been optimized away by "purge".
-  EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (5.3, 0.0))), "(null)");
+  EXPECT_EQ (qnet_name (l2n.probe_net (*rmetal1, db::DPoint (5.3, 0.0))), "RINGO:VSS");
 }
 
 TEST(6_MoreDeviceTypes)