diff --git a/kotlin/reflect/src/main/java/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapter.kt b/kotlin/reflect/src/main/java/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapter.kt
index 3bc8eaa..d32ae5c 100644
--- a/kotlin/reflect/src/main/java/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapter.kt
+++ b/kotlin/reflect/src/main/java/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapter.kt
@@ -17,6 +17,7 @@ package com.squareup.moshi.kotlin.reflect
 
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonAdapter
+import com.squareup.moshi.JsonClass
 import com.squareup.moshi.JsonDataException
 import com.squareup.moshi.JsonReader
 import com.squareup.moshi.JsonWriter
@@ -173,6 +174,8 @@ class KotlinJsonAdapterFactory : JsonAdapter.Factory {
     if (rawType.isEnum) return null
     if (!rawType.isAnnotationPresent(KOTLIN_METADATA)) return null
     if (Util.isPlatformType(rawType)) return null
+    val jsonClass = rawType.getAnnotation(JsonClass::class.java)
+    if (jsonClass != null && jsonClass.generateAdapter) return null
 
     if (rawType.isLocalClass) {
       throw IllegalArgumentException("Cannot serialize local class or object expression ${rawType.name}")
diff --git a/kotlin/tests/src/test/kotlin/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapterTest.kt b/kotlin/tests/src/test/kotlin/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapterTest.kt
index f671d60..7ee003a 100644
--- a/kotlin/tests/src/test/kotlin/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapterTest.kt
+++ b/kotlin/tests/src/test/kotlin/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapterTest.kt
@@ -17,6 +17,7 @@ package com.squareup.moshi.kotlin.reflect
 
 import com.squareup.moshi.FromJson
 import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
 import com.squareup.moshi.JsonDataException
 import com.squareup.moshi.JsonQualifier
 import com.squareup.moshi.Moshi
@@ -840,6 +841,25 @@ class KotlinJsonAdapterTest {
     assertThat(adapter.toJson(value)).isEqualTo(json)
   }
 
+  @Test fun mixingReflectionAndCodegen() {
+    val moshi = Moshi.Builder()
+        .add(KotlinJsonAdapterFactory())
+        .build()
+    val generatedAdapter = moshi.adapter(UsesGeneratedAdapter::class.java)
+    val reflectionAdapter = moshi.adapter(UsesReflectionAdapter::class.java)
+
+    assertThat(generatedAdapter.javaClass.name)
+        .contains("KotlinJsonAdapterTest_UsesGeneratedAdapterJsonAdapter")
+    assertThat(reflectionAdapter.javaClass.name)
+        .doesNotContain("KotlinJsonAdapterTest_UsesReflectionAdapterJsonAdapter")
+  }
+
+  @JsonClass(generateAdapter = true)
+  class UsesGeneratedAdapter(var a: Int, var b: Int)
+
+  @JsonClass(generateAdapter = false)
+  class UsesReflectionAdapter(var a: Int, var b: Int)
+
   @Retention(RUNTIME)
   @JsonQualifier
   annotation class Uppercase