diff --git a/src/test/java/ubc/pavlab/rdp/validation/EmailValidatorTest.java b/src/test/java/ubc/pavlab/rdp/validation/EmailValidatorTest.java
index 81c6cb5f..40a061c6 100644
--- a/src/test/java/ubc/pavlab/rdp/validation/EmailValidatorTest.java
+++ b/src/test/java/ubc/pavlab/rdp/validation/EmailValidatorTest.java
@@ -45,6 +45,14 @@ public void validate_whenIdnIsEnabledAndDomainHasUnicodeSymbols_thenAccept() {
         verifyNoInteractions( e );
     }
 
+    @Test
+    public void validate_whenIdnIsEnabledAndDomainHasInvalidUnicodeSymbols_thenReject() {
+        v = new EmailValidator( (AllowedDomainStrategy) null, true );
+        // that's the code for a chequered flag 🏁
+        v.validate( "foo@B\uD83C\uDFC1cher.example", e );
+        verify( e ).rejectValue( isNull(), eq( "EmailValidator.domainNotConformToRfc3490" ), any(), isNull() );
+    }
+
     @Test
     public void validate_whenDomainContainsUnsupportedCharacters_thenReject() {
         v.validate( "foo@Bücher.example", e );