diff --git a/networking/src/main/java/google/registry/networking/handler/SslClientInitializer.java b/networking/src/main/java/google/registry/networking/handler/SslClientInitializer.java
index 15c5781ab..6c4bfc809 100644
--- a/networking/src/main/java/google/registry/networking/handler/SslClientInitializer.java
+++ b/networking/src/main/java/google/registry/networking/handler/SslClientInitializer.java
@@ -106,7 +106,7 @@ public class SslClientInitializer<C extends Channel> extends ChannelInitializer<
         SslContextBuilder.forClient()
             .sslProvider(sslProvider)
             .trustManager(
-                trustedCertificates.isEmpty()
+                trustedCertificates == null || trustedCertificates.isEmpty()
                     ? null
                     : trustedCertificates.toArray(new X509Certificate[0]));