diff --git a/core/src/test/java/google/registry/flows/domain/DomainUpdateFlowTest.java b/core/src/test/java/google/registry/flows/domain/DomainUpdateFlowTest.java
index 48b0f0134..745803ab4 100644
--- a/core/src/test/java/google/registry/flows/domain/DomainUpdateFlowTest.java
+++ b/core/src/test/java/google/registry/flows/domain/DomainUpdateFlowTest.java
@@ -919,7 +919,7 @@ class DomainUpdateFlowTest extends ResourceFlowTestCase<DomainUpdateFlow, Domain
             .addStatusValue(SERVER_UPDATE_PROHIBITED)
             .build());
     Exception e = assertThrows(ResourceStatusProhibitsOperationException.class, this::runFlow);
-    assertThat(e).hasMessageThat().containsMatch("serverUpdateProhibited");
+    assertThat(e).hasMessageThat().contains("serverUpdateProhibited");
   }
 
   @Test
@@ -937,7 +937,7 @@ class DomainUpdateFlowTest extends ResourceFlowTestCase<DomainUpdateFlow, Domain
     persistReferencedEntities();
     persistDomain();
     Exception e = assertThrows(StatusNotClientSettableException.class, this::runFlow);
-    assertThat(e).hasMessageThat().containsMatch("serverUpdateProhibited");
+    assertThat(e).hasMessageThat().contains("serverUpdateProhibited");
   }
 
   @Test
diff --git a/core/src/test/java/google/registry/flows/poll/PollAckFlowTest.java b/core/src/test/java/google/registry/flows/poll/PollAckFlowTest.java
index 8bca996c8..91f36c0cd 100644
--- a/core/src/test/java/google/registry/flows/poll/PollAckFlowTest.java
+++ b/core/src/test/java/google/registry/flows/poll/PollAckFlowTest.java
@@ -174,9 +174,7 @@ class PollAckFlowTest extends FlowTestCase<PollAckFlow> {
   void testFailure_noSuchMessage() throws Exception {
     assertTransactionalFlow(true);
     Exception e = assertThrows(MessageDoesNotExistException.class, this::runFlow);
-    assertThat(e)
-        .hasMessageThat()
-        .containsMatch(String.format("(1-3-EXAMPLE-4-%d-2011)", MESSAGE_ID));
+    assertThat(e).hasMessageThat().contains(String.format("(1-3-EXAMPLE-4-%d-2011)", MESSAGE_ID));
   }
 
   @Test
@@ -255,8 +253,6 @@ class PollAckFlowTest extends FlowTestCase<PollAckFlow> {
             .build());
     assertTransactionalFlow(true);
     Exception e = assertThrows(MessageDoesNotExistException.class, this::runFlow);
-    assertThat(e)
-        .hasMessageThat()
-        .containsMatch(String.format("(1-3-EXAMPLE-4-%d-2011)", MESSAGE_ID));
+    assertThat(e).hasMessageThat().contains(String.format("(1-3-EXAMPLE-4-%d-2011)", MESSAGE_ID));
   }
 }
diff --git a/core/src/test/java/google/registry/tmch/TmchCertificateAuthorityTest.java b/core/src/test/java/google/registry/tmch/TmchCertificateAuthorityTest.java
index 9b4c1e703..dbd7075e3 100644
--- a/core/src/test/java/google/registry/tmch/TmchCertificateAuthorityTest.java
+++ b/core/src/test/java/google/registry/tmch/TmchCertificateAuthorityTest.java
@@ -53,7 +53,7 @@ class TmchCertificateAuthorityTest {
     CertificateExpiredException e =
         assertThrows(
             CertificateExpiredException.class, tmchCertificateAuthority::getAndValidateRoot);
-    assertThat(e).hasMessageThat().containsMatch("NotAfter: Sun Jul 23 23:59:59 UTC 2023");
+    assertThat(e).hasMessageThat().contains("NotAfter: Sun Jul 23 23:59:59 UTC 2023");
   }
 
   @Test
@@ -64,7 +64,7 @@ class TmchCertificateAuthorityTest {
     CertificateNotYetValidException e =
         assertThrows(
             CertificateNotYetValidException.class, tmchCertificateAuthority::getAndValidateRoot);
-    assertThat(e).hasMessageThat().containsMatch("NotBefore: Wed Jul 24 00:00:00 UTC 2013");
+    assertThat(e).hasMessageThat().contains("NotBefore: Wed Jul 24 00:00:00 UTC 2013");
   }
 
   @Test
diff --git a/core/src/test/java/google/registry/tools/CompareDbBackupsTest.java b/core/src/test/java/google/registry/tools/CompareDbBackupsTest.java
index 083d56149..dbbc7f043 100644
--- a/core/src/test/java/google/registry/tools/CompareDbBackupsTest.java
+++ b/core/src/test/java/google/registry/tools/CompareDbBackupsTest.java
@@ -61,7 +61,7 @@ public class CompareDbBackupsTest {
     URL backupRootFolder = Resources.getResource("google/registry/tools/datastore-export");
     CompareDbBackups.main(new String[] {backupRootFolder.getPath(), backupRootFolder.getPath()});
     String output = new String(stdout.toByteArray(), UTF_8);
-    assertThat(output).containsMatch("Both sets have the same 41 entities");
+    assertThat(output).contains("Both sets have the same 41 entities");
   }
 
   @Test