diff --git a/plugin/src/main/kotlin/dev/inmo/plagubot/HelloPlugin.kt b/plugin/src/main/kotlin/dev/inmo/plagubot/HelloPlugin.kt
index c6a388b..7929336 100644
--- a/plugin/src/main/kotlin/dev/inmo/plagubot/HelloPlugin.kt
+++ b/plugin/src/main/kotlin/dev/inmo/plagubot/HelloPlugin.kt
@@ -26,7 +26,7 @@ object HelloPlugin : Plugin {
     )
 
     override fun Module.setupDI(config: JsonObject) {
-        registerConfig<HelloPluginConfig>("helloPlugin")
+        registerConfig<HelloPluginConfig>("helloPlugin") { null }
     }
 
     private sealed interface InternalFSMState : State {
diff --git a/plugin/src/main/kotlin/dev/inmo/plagubot/KoinExtensions.kt b/plugin/src/main/kotlin/dev/inmo/plagubot/KoinExtensions.kt
index c230e65..33a4cae 100644
--- a/plugin/src/main/kotlin/dev/inmo/plagubot/KoinExtensions.kt
+++ b/plugin/src/main/kotlin/dev/inmo/plagubot/KoinExtensions.kt
@@ -20,16 +20,18 @@ val Koin.database: Database
 /**
  * Using [single] to register `T` with serializer [configSerializer]
  *
- * @param optional If passed, absence of [field] in config will lead to null config value in koin. If passed as false
- * (default), absence of [field] in config will lead to an error
+ * @param default Will be used if [field] is absent as an alternative way of config allocation. If null passed, error
+ * will be thrown
  */
-inline fun <reified T> Module.registerConfig(configSerializer: KSerializer<T>, field: String?, optional: Boolean = false) {
+inline fun <reified T> Module.registerConfig(configSerializer: KSerializer<T>, field: String?, noinline default: (Scope.(JsonObject) -> T?)? = null) {
     single {
         val fieldValue = get<JsonObject>().let {
             if (field == null) {
                 it
             } else {
-                it[field] ?: if (optional) return@single null else error("Unable to take field $field from config")
+                it[field] ?: default ?.let { _ ->
+                    return@single default(it)
+                } ?: error("Unable to take field $field from config")
             }
         }
         get<Json>().decodeFromJsonElement(configSerializer, fieldValue)
@@ -39,19 +41,19 @@ inline fun <reified T> Module.registerConfig(configSerializer: KSerializer<T>, f
 /**
  * Using [single] to register config with getting of [serializer] from [kClass]
  *
- * @param optional If passed, absence of [field] in config will lead to null config value in koin. If passed as false
- * (default), absence of [field] in config will lead to an error
+ * @param default Will be used if [field] is absent as an alternative way of config allocation. If null passed, error
+ * will be thrown
  */
 @OptIn(InternalSerializationApi::class)
-inline fun <reified T : Any> Module.registerConfig(kClass: KClass<T>, field: String?, optional: Boolean = false) = registerConfig(kClass.serializer(), field, optional)
+inline fun <reified T : Any> Module.registerConfig(kClass: KClass<T>, field: String?, noinline default: (Scope.(JsonObject) -> T?)? = null) = registerConfig(kClass.serializer(), field, default)
 
 /**
  * Using [single] to register config with getting of [serializer] from [kClass]
  *
- * @param optional If passed, absence of [field] in config will lead to null config value in koin. If passed as false
- * (default), absence of [field] in config will lead to an error
+ * @param default Will be used if [field] is absent as an alternative way of config allocation. If null passed, error
+ * will be thrown
  */
-inline fun <reified T : Any> Module.registerConfig(field: String?, optional: Boolean = false) = registerConfig(T::class, field, optional)
+inline fun <reified T : Any> Module.registerConfig(field: String?, noinline default: (Scope.(JsonObject) -> T?)? = null) = registerConfig(T::class, field, default)
 
 inline fun <reified T : Any> Scope.config() = get<T>()
 inline fun <reified T : Any> Koin.config() = get<T>()