diff --git a/src/main/kotlin/net/thauvin/erik/bitly/config/CreateConfig.kt b/src/main/kotlin/net/thauvin/erik/bitly/config/CreateConfig.kt
index c90519d..017e04f 100644
--- a/src/main/kotlin/net/thauvin/erik/bitly/config/CreateConfig.kt
+++ b/src/main/kotlin/net/thauvin/erik/bitly/config/CreateConfig.kt
@@ -40,23 +40,14 @@ import net.thauvin.erik.bitly.config.deeplinks.CreateDeeplinks
  * See the [Bit.ly API](https://dev.bitly.com/api-reference#createFullBitlink) for more information.
  */
 @Suppress("LocalVariableName", "PropertyName")
-class CreateConfig @JvmOverloads constructor(
-    var long_url: String,
-    var domain: String = Constants.EMPTY,
-    var group_guid: String = Constants.EMPTY,
-    var title: String = Constants.EMPTY,
-    var tags: Array<String> = emptyArray(),
-    var deeplinks: CreateDeeplinks = CreateDeeplinks(),
-    var toJson: Boolean = false
-) {
-    constructor(builder: Builder) : this(builder.long_url) {
-        domain = builder.domain
-        group_guid = builder.group_guid
-        title = builder.title
-        tags = builder.tags
-        deeplinks = builder.deeplinks
-        toJson = builder.toJson
-    }
+class CreateConfig private constructor(builder: Builder) {
+    val long_url = builder.long_url
+    val domain = builder.domain
+    val group_guid = builder.group_guid
+    val title = builder.title
+    val tags = builder.tags
+    val deeplinks = builder.deeplinks
+    val toJson = builder.toJson
 
     /**
      * Configures the creation parameters of a Bitlink.
diff --git a/src/main/kotlin/net/thauvin/erik/bitly/config/UpdateConfig.kt b/src/main/kotlin/net/thauvin/erik/bitly/config/UpdateConfig.kt
index 3985d71..e837c49 100644
--- a/src/main/kotlin/net/thauvin/erik/bitly/config/UpdateConfig.kt
+++ b/src/main/kotlin/net/thauvin/erik/bitly/config/UpdateConfig.kt
@@ -39,21 +39,13 @@ import net.thauvin.erik.bitly.config.deeplinks.UpdateDeeplinks
  *
  * See the [Bit.ly API](https://dev.bitly.com/api-reference#updateBitlink) for more information.
  */
-class UpdateConfig @JvmOverloads constructor(
-    var bitlink: String,
-    var title: String = Constants.EMPTY,
-    var archived: Boolean = false,
-    var tags: Array<String> = emptyArray(),
-    var deeplinks: UpdateDeeplinks = UpdateDeeplinks(),
-    var toJson: Boolean = false
-) {
-    constructor(builder: Builder) : this(builder.bitlink) {
-        title = builder.title
-        archived = builder.archived
-        tags = builder.tags
-        deeplinks = builder.deeplinks
-        toJson = builder.toJson
-    }
+class UpdateConfig private constructor(builder: Builder) {
+    val bitlink = builder.bitlink
+    val title = builder.title
+    val archived = builder.archived
+    val tags = builder.tags
+    val deeplinks = builder.deeplinks
+    val toJson = builder.toJson
 
     /**
      * Configures the update parameters of a Bitlink.
diff --git a/src/test/kotlin/net/thauvin/erik/bitly/config/ConfigTest.kt b/src/test/kotlin/net/thauvin/erik/bitly/config/ConfigTest.kt
index dad8a8c..57a7ae3 100644
--- a/src/test/kotlin/net/thauvin/erik/bitly/config/ConfigTest.kt
+++ b/src/test/kotlin/net/thauvin/erik/bitly/config/ConfigTest.kt
@@ -34,9 +34,9 @@ package net.thauvin.erik.bitly.config
 import assertk.assertThat
 import assertk.assertions.isEqualTo
 import net.thauvin.erik.bitly.config.deeplinks.CreateDeeplinks
+import net.thauvin.erik.bitly.config.deeplinks.UpdateDeeplinks
 import net.thauvin.erik.bitly.config.deeplinks.enums.InstallType
 import net.thauvin.erik.bitly.config.deeplinks.enums.Os
-import net.thauvin.erik.bitly.config.deeplinks.UpdateDeeplinks
 import org.json.JSONObject
 import kotlin.test.Test
 
@@ -48,14 +48,13 @@ class ConfigTest {
             install_type(InstallType.AUTO_INSTALL)
         }
 
-        val config = CreateConfig(
-            "long_url",
-            "domain",
-            "group_guid",
-            "title",
-            arrayOf("tag", "tag2"),
-            deeplinks,
-        )
+        val config = CreateConfig.Builder("long_url")
+            .domain("domain")
+            .groupGuid("group_guid")
+            .title("title")
+            .tags(arrayOf("tag", "tag2"))
+            .deeplinks(deeplinks)
+            .build()
 
         val map = mapOf(
             "long_url" to config.long_url,
@@ -81,13 +80,13 @@ class ConfigTest {
             app_guid("app_guid")
         }
 
-        val config = UpdateConfig(
-            "blink",
-            "title",
-            true,
-            arrayOf("tag", "tag2"),
-            deeplinks
-        )
+        val config = UpdateConfig.Builder("blink")
+            .title("title")
+            .archived(true)
+            .tags(arrayOf("tag", "tag2"))
+            .deeplinks(deeplinks)
+            .build()
+
         val map = mapOf(
             "bitlink" to config.bitlink,
             "title" to config.title,