diff --git a/runtime/src/commonMain/kotlin/pbandk/internal/json/JsonMessageEncoder.kt b/runtime/src/commonMain/kotlin/pbandk/internal/json/JsonMessageEncoder.kt
index a90d3b5f..25f2a361 100644
--- a/runtime/src/commonMain/kotlin/pbandk/internal/json/JsonMessageEncoder.kt
+++ b/runtime/src/commonMain/kotlin/pbandk/internal/json/JsonMessageEncoder.kt
@@ -38,8 +38,8 @@ internal class JsonMessageEncoder(private val jsonConfig: JsonConfig) : MessageE
             @Suppress("UNCHECKED_CAST")
             val value = (fd.value as KProperty1<T, *>).get(message)
 
-            if (value == null && fd.oneofMember) continue
-            if (!fd.oneofMember && !jsonConfig.outputDefaultValues && fd.type.isDefaultValue(value)) continue
+            if (value == null && fd.type.hasPresence) continue
+            if (!fd.type.hasPresence && !jsonConfig.outputDefaultValues && fd.type.isDefaultValue(value)) continue
 
             val jsonValue = value
                 ?.takeUnless {
diff --git a/runtime/src/commonTest/kotlin/pbandk/json/OutputDefaultValuesTest.kt b/runtime/src/commonTest/kotlin/pbandk/json/OutputDefaultValuesTest.kt
index df083328..3002dcda 100644
--- a/runtime/src/commonTest/kotlin/pbandk/json/OutputDefaultValuesTest.kt
+++ b/runtime/src/commonTest/kotlin/pbandk/json/OutputDefaultValuesTest.kt
@@ -32,12 +32,12 @@ class OutputDefaultValuesTest {
         assertEquals(JsonPrimitive(""), parsedJson["optionalBytes"])
         assertEquals(JsonPrimitive(TestAllTypesProto3.NestedEnum.fromValue(0).name!!), parsedJson["optionalNestedEnum"])
 
-        assertEquals(JsonNull, parsedJson["optionalNestedMessage"])
+        assertFalse("optionalNestedMessage" in parsedJson)
 
         assertEquals(JsonArray(emptyList()), parsedJson["repeatedString"])
         assertEquals(JsonObject(emptyMap()), parsedJson["mapBoolBool"])
 
-        assertEquals(JsonNull, parsedJson["optionalStringWrapper"])
+        assertFalse("optionalStringWrapper" in parsedJson)
         assertEquals(JsonPrimitive(false), parsedJson["optionalBoolWrapper"])
     }
 
@@ -55,13 +55,13 @@ class OutputDefaultValuesTest {
     @Test
     fun testProto2EnumUnsetField() {
         val message = MessageWithEnum()
-        assertEquals("{\"value\":null}", message.encodeToJsonString(jsonConfigCompactOutput))
+        assertEquals("{}", message.encodeToJsonString(jsonConfigCompactOutput))
     }
 
     @Test
     fun testProto2EnumFieldSetToDefaultValue() {
         val message = MessageWithEnum(value = MessageWithEnum.EnumType.FOO)
-        assertEquals("{}", message.encodeToJsonString(jsonConfigCompactOutput))
+        assertEquals("{\"value\":\"FOO\"}", message.encodeToJsonString(jsonConfigCompactOutput))
     }
 
     @Test