diff --git a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/ImageConfiguration.java b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/ImageConfiguration.java
index ceea789b7e..4170306afc 100644
--- a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/ImageConfiguration.java
+++ b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/ImageConfiguration.java
@@ -23,6 +23,7 @@
 import org.gradle.api.Action;
 import org.gradle.api.model.ObjectFactory;
 import org.gradle.api.tasks.Input;
+import org.gradle.api.tasks.Internal;
 import org.gradle.api.tasks.Nested;
 import org.gradle.api.tasks.Optional;
 
@@ -78,6 +79,7 @@ public void auth(Action<? super AuthConfiguration> action) {
   }
 
   /** Converts the {@link ImageConfiguration} to an {@link Authorization}. */
+  @Internal
   @Nullable
   Authorization getImageAuthorization() {
     if (auth.getUsername() == null || auth.getPassword() == null) {