diff --git a/rest-endpoint/src/main/kotlin/tech/b180/cordaptor/rest/CordaTypesSerializers.kt b/rest-endpoint/src/main/kotlin/tech/b180/cordaptor/rest/CordaTypesSerializers.kt
index 90de9cd..1a4caf0 100644
--- a/rest-endpoint/src/main/kotlin/tech/b180/cordaptor/rest/CordaTypesSerializers.kt
+++ b/rest-endpoint/src/main/kotlin/tech/b180/cordaptor/rest/CordaTypesSerializers.kt
@@ -210,7 +210,7 @@ class JavaInstantSerializer : CustomSerializer<Instant>,
 }
 
 /**
- * Serializer for an [Duration] representing it as a JSON string value formatted as an ISO-8601 timestamp.
+ * Serializer for an [Duration] representing it as a JSON string value formatted as an ISO-8601 duration format.
  *
  * @see DateTimeFormatter.ISO_INSTANT
  */
@@ -224,7 +224,7 @@ class JavaDurationSerializer : CustomSerializer<Duration>,
   override fun generateSchema(generator: JsonSchemaGenerator): JsonObject {
     return mapOf(
             "type" to "string",
-            "format" to "date-time"
+            "format" to "iso-8601-duration"
     ).asJsonObject()
   }
 }
diff --git a/rest-endpoint/src/test/kotlin/tech/b180/cordaptor/rest/CordaTypesTest.kt b/rest-endpoint/src/test/kotlin/tech/b180/cordaptor/rest/CordaTypesTest.kt
index 1084c4c..15d697a 100644
--- a/rest-endpoint/src/test/kotlin/tech/b180/cordaptor/rest/CordaTypesTest.kt
+++ b/rest-endpoint/src/test/kotlin/tech/b180/cordaptor/rest/CordaTypesTest.kt
@@ -281,7 +281,7 @@ class CordaTypesTest : KoinTest {
     fun `test java duration serialization`() {
         val serializer = getKoin().getSerializer(Duration::class)
 
-        assertEquals("""{"type":"string","format":"date-time"}""".asJsonObject(),
+        assertEquals("""{"type":"string","format":"iso-8601-duration"}""".asJsonObject(),
                 serializer.generateRecursiveSchema(getKoin().get()))
 
         // "PT4H" is string for duration of 4 hours