diff --git a/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerOptions.java b/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerOptions.java
index 0ef5516d27..f898b8f88f 100644
--- a/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerOptions.java
+++ b/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerOptions.java
@@ -20,6 +20,7 @@
 import com.google.api.gax.grpc.GrpcInterceptorProvider;
 import com.google.api.gax.retrying.RetrySettings;
 import com.google.api.gax.rpc.TransportChannelProvider;
+import com.google.cloud.NoCredentials;
 import com.google.cloud.ServiceDefaults;
 import com.google.cloud.ServiceOptions;
 import com.google.cloud.ServiceRpc;
@@ -518,6 +519,8 @@ public ManagedChannelBuilder apply(ManagedChannelBuilder builder) {
                 return builder.usePlaintext();
               }
             });
+        // As we are using plain text, we should never send any credentials.
+        this.setCredentials(NoCredentials.getInstance());
       }
       return new SpannerOptions(this);
     }