Invert logic

1 files changed, 1 insertions, 1 deletions

diff --git a/document/src/main/java/com/yahoo/document/idstring/IdString.java b/document/src/main/java/com/yahoo/document/idstring/IdString.java
index 82a01377b6c..40ac19dec6d 100644
--- a/document/src/main/java/com/yahoo/document/idstring/IdString.java
+++ b/document/src/main/java/com/yahoo/document/idstring/IdString.java
@@ -79,7 +79,7 @@ public abstract class IdString {
     }
 
     private static void validateTextString(String id) {
-        if (Text.isValidTextString(id)) {
+        if ( ! Text.isValidTextString(id)) {
             throw new IllegalArgumentException("Unparseable id '" + id + "': Contains illegal code point 0x" +
                     Integer.toHexString(Text.validateTextString(id).getAsInt()).toUpperCase());
         }