diff --git a/src/libraries/System.ComponentModel.Annotations/tests/System/ComponentModel/DataAnnotations/RegularExpressionAttributeTests.cs b/src/libraries/System.ComponentModel.Annotations/tests/System/ComponentModel/DataAnnotations/RegularExpressionAttributeTests.cs
index 45a9da9712f262..99a9831a3e6f9e 100644
--- a/src/libraries/System.ComponentModel.Annotations/tests/System/ComponentModel/DataAnnotations/RegularExpressionAttributeTests.cs
+++ b/src/libraries/System.ComponentModel.Annotations/tests/System/ComponentModel/DataAnnotations/RegularExpressionAttributeTests.cs
@@ -78,7 +78,7 @@ public static void Validate_InvalidMatchTimeoutInMilliseconds_ThrowsArgumentOutO
         public static void Validate_MatchingTimesOut_ThrowsRegexMatchTimeoutException()
         {
             RegularExpressionAttribute attribute = new RegularExpressionAttribute("(a[ab]+)+$") { MatchTimeoutInMilliseconds = 1 };
-            Assert.Throws<RegexMatchTimeoutException>(() => attribute.Validate("aaaaaaaaaaaaaaaaaaaaaaaaaaaa>", new ValidationContext(new object())));
+            Assert.Throws<RegexMatchTimeoutException>(() => attribute.Validate(new string('a', 100) + ">", new ValidationContext(new object())));
         }
 
         [Fact]