diff --git a/src/libraries/System.Net.Security/tests/FunctionalTests/TestConfiguration.cs b/src/libraries/System.Net.Security/tests/FunctionalTests/TestConfiguration.cs
index c59da067c869b1..d6a89d8ced0668 100644
--- a/src/libraries/System.Net.Security/tests/FunctionalTests/TestConfiguration.cs
+++ b/src/libraries/System.Net.Security/tests/FunctionalTests/TestConfiguration.cs
@@ -3,6 +3,7 @@
 
 using System.Diagnostics;
 using System.IO;
+using System.Runtime.InteropServices;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading.Tasks;