diff --git a/src/test/java/com/mythlane/gravityflip/command/DefineValidationTest.java b/src/test/java/com/mythlane/gravityflip/command/DefineValidationTest.java
index d39128b..5ebeffd 100644
--- a/src/test/java/com/mythlane/gravityflip/command/DefineValidationTest.java
+++ b/src/test/java/com/mythlane/gravityflip/command/DefineValidationTest.java
@@ -36,6 +36,11 @@ class DefineValidationTest {
         assertFalse(DefineValidation.isValidName(""));
         assertFalse(DefineValidation.isValidName(" "));
         assertFalse(DefineValidation.isValidName("my zone"));
+        // B4 UAT regression — quoted arg with spaces must be rejected
+        assertFalse(DefineValidation.isValidName("nom avec espaces"));
+        assertFalse(DefineValidation.isValidName("a\tb"));
+        assertFalse(DefineValidation.isValidName(" leading"));
+        assertFalse(DefineValidation.isValidName("trailing "));
         assertFalse(DefineValidation.isValidName("a".repeat(33)));
         assertFalse(DefineValidation.isValidName("name!"));
         assertFalse(DefineValidation.isValidName("名前"));