diff --git a/build.gradle.kts b/build.gradle.kts
index dec0161..9be4eab 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -73,7 +73,8 @@ dependencies {
 
     implementation("org.leadpony.justify:justify:3.1.0")
 
-    implementation("dev.harrel:json-schema:1.4.3")
+    implementation("dev.harrel:json-schema:1.5.0")
+    implementation("com.sanctionco.jmail:jmail:1.6.2") // dev.harrel format validation
 
     implementation("org.apache.logging.log4j:log4j-core:$log4jVersion")
     runtimeOnly("org.apache.logging.log4j:log4j-slf4j2-impl:$log4jVersion")
diff --git a/src/main/java/org/creekservice/kafka/test/perf/implementations/DevHarrelImplementation.java b/src/main/java/org/creekservice/kafka/test/perf/implementations/DevHarrelImplementation.java
index cb71066..2d14410 100644
--- a/src/main/java/org/creekservice/kafka/test/perf/implementations/DevHarrelImplementation.java
+++ b/src/main/java/org/creekservice/kafka/test/perf/implementations/DevHarrelImplementation.java
@@ -23,6 +23,7 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.json.JsonMapper;
 import dev.harrel.jsonschema.Dialects;
+import dev.harrel.jsonschema.FormatEvaluatorFactory;
 import dev.harrel.jsonschema.JsonNode;
 import dev.harrel.jsonschema.SchemaResolver;
 import dev.harrel.jsonschema.SpecificationVersion;
@@ -139,6 +140,7 @@ private Validator validator(final SchemaSpec spec, final AdditionalSchemas addit
                         new dev.harrel.jsonschema.ValidatorFactory()
                                 .withDisabledSchemaValidation(true)
                                 .withDialect(new Dialects.Draft2020Dialect())
+                                .withEvaluatorFactory(new FormatEvaluatorFactory())
                                 .withJsonNodeFactory(nodeFactory)
                                 .withSchemaResolver(resolver)
                                 .createValidator();
@@ -150,6 +152,7 @@ private Validator validator(final SchemaSpec spec, final AdditionalSchemas addit
                         new dev.harrel.jsonschema.ValidatorFactory()
                                 .withDisabledSchemaValidation(true)
                                 .withDialect(new Dialects.Draft2019Dialect())
+                                .withEvaluatorFactory(new FormatEvaluatorFactory())
                                 .withJsonNodeFactory(nodeFactory)
                                 .withSchemaResolver(resolver)
                                 .createValidator();