diff --git a/java-tests/runtime/src/test/kotlin/io/spine/validate/EnclosedMessageValidationSpec.kt b/java-tests/runtime/src/test/kotlin/io/spine/validate/EnclosedMessageValidationSpec.kt
index 670dcef0..343d40f1 100644
--- a/java-tests/runtime/src/test/kotlin/io/spine/validate/EnclosedMessageValidationSpec.kt
+++ b/java-tests/runtime/src/test/kotlin/io/spine/validate/EnclosedMessageValidationSpec.kt
@@ -98,7 +98,7 @@ internal class EnclosedMessageValidationSpec : ValidationOfConstraintTest() {
         validate(msg)
 
         val violation = singleViolation()
-        violation.message.format() shouldContain "is invalid"
+        violation.message.formatUnsafe() shouldContain "is invalid"
         assertFieldPathIs(
             violation,
             ENCLOSED_FIELD_NAME
diff --git a/java-tests/runtime/src/test/kotlin/io/spine/validate/ValidationOfConstraintTest.kt b/java-tests/runtime/src/test/kotlin/io/spine/validate/ValidationOfConstraintTest.kt
index 8a025eca..ed6abbb5 100644
--- a/java-tests/runtime/src/test/kotlin/io/spine/validate/ValidationOfConstraintTest.kt
+++ b/java-tests/runtime/src/test/kotlin/io/spine/validate/ValidationOfConstraintTest.kt
@@ -31,6 +31,9 @@ import com.google.protobuf.Message
 import io.kotest.matchers.collections.shouldBeEmpty
 import io.kotest.matchers.collections.shouldHaveSize
 import io.kotest.matchers.shouldBe
+import io.kotest.matchers.string.shouldContain
+import io.kotest.matchers.string.shouldNotBeEmpty
+import io.kotest.matchers.string.shouldNotContain
 import io.spine.validate.Validate.violationsOf
 import org.junit.jupiter.api.Assertions.assertDoesNotThrow
 import org.junit.jupiter.api.assertThrows
@@ -152,11 +155,7 @@ abstract class ValidationOfConstraintTest {
 
         private fun assertHasCorrectFormat(violation: ConstraintViolation?) {
             val template = violation!!.message.withPlaceholders
-            val placeholders = violation.message.placeholderValueMap
-            assertThat(template).isNotEmpty()
-            assertDoesNotThrow {
-                checkPlaceholdersHasValue(template, placeholders)
-            }
+            template.shouldNotBeEmpty()
         }
 
         private fun assertHasFieldPath(violation: ConstraintViolation?) {
diff --git a/java-tests/validating/src/testFixtures/kotlin/io/spine/validation/assertions/Assertions.kt b/java-tests/validating/src/testFixtures/kotlin/io/spine/validation/assertions/Assertions.kt
index a35e322c..939cbdde 100644
--- a/java-tests/validating/src/testFixtures/kotlin/io/spine/validation/assertions/Assertions.kt
+++ b/java-tests/validating/src/testFixtures/kotlin/io/spine/validation/assertions/Assertions.kt
@@ -37,7 +37,7 @@ import io.kotest.matchers.string.shouldContain
 import io.spine.type.toJson
 import io.spine.validate.ConstraintViolation
 import io.spine.validate.ValidationException
-import io.spine.validate.format
+import io.spine.validate.formatUnsafe
 import org.junit.jupiter.api.Assertions.assertDoesNotThrow
 import org.junit.jupiter.api.Assertions.assertThrows
 import org.junit.jupiter.api.Assertions.fail
@@ -90,7 +90,7 @@ fun assertViolation(
         .contains(field)
 
     val violation = violations.atField(field)
-    violation.message.format() shouldContain errorMessagePart
+    violation.message.formatUnsafe() shouldContain errorMessagePart
 }
 
 /**