diff --git a/src/org/labkey/test/util/TestDataGenerator.java b/src/org/labkey/test/util/TestDataGenerator.java
index bdb3d5220c..bfe88142f5 100644
--- a/src/org/labkey/test/util/TestDataGenerator.java
+++ b/src/org/labkey/test/util/TestDataGenerator.java
@@ -723,7 +723,7 @@ private static boolean isNameInvalidLocal(DomainKind domainKind, @Nullable Rando
 
             int maxLength = switch (domainKind)
             {
-                case Assay -> 200 - 13; // Make room for "{$domainName} Batch Fields" domain
+                case Assay -> 150; // Make room for "{$domainName} Batch Fields" domain
                 case SampleSet -> 100;
                 default -> 200; // Sources, lists, and datasets allow 200 character names
             };