1 files changed, 4 insertions, 2 deletions
diff --git a/document/src/test/java/com/yahoo/document/DocumentIdTestCase.java b/document/src/test/java/com/yahoo/document/DocumentIdTestCase.java
index a0c5da52ff7..fea3b265b6d 100644
--- a/document/src/test/java/com/yahoo/document/DocumentIdTestCase.java
+++ b/document/src/test/java/com/yahoo/document/DocumentIdTestCase.java
@@ -16,8 +16,10 @@ import java.io.UnsupportedEncodingException;
 import java.util.regex.Pattern;
 import java.util.Arrays;
 
+import static org.hamcrest.Matchers.containsString;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
@@ -225,7 +227,7 @@ public class DocumentIdTestCase {
             new DocumentId(strId);
             fail("Expected an IllegalArgumentException to be thrown");
         } catch (IllegalArgumentException ex) {
-            assertTrue(ex.getMessage().contains(exceptionMsg));
+            assertThat(ex.getMessage(), containsString(exceptionMsg));
         }
     }
 
@@ -252,7 +254,7 @@ public class DocumentIdTestCase {
             DocumentId.createFromSerialized(strId);
             fail("Expected an IllegalArgumentException to be thrown");
         } catch (IllegalArgumentException ex) {
-            assertTrue(ex.getMessage().contains("illegal zero byte code point"));
+            assertThat(ex.getMessage(), containsString("illegal zero byte code point"));
         }
     }