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 2e6c6ff..ef4aa97 100644
--- a/src/main/kotlin/net/thauvin/erik/bitly/config/CreateConfig.kt
+++ b/src/main/kotlin/net/thauvin/erik/bitly/config/CreateConfig.kt
@@ -71,28 +71,28 @@ class CreateConfig private constructor(builder: Builder) {
         /**
          * A branded short domain or `bit.ly` by default.
          */
-        fun domain(domain: String) = apply { this.domain = domain }
+        fun domain(domain: String): Builder = apply { this.domain = domain }
 
         /**
          * Always include a specific group and custom domain in your shorten calls.
          */
-        fun groupGuid(group_guid: String) = apply { this.group_guid = group_guid }
+        fun groupGuid(group_guid: String): Builder = apply { this.group_guid = group_guid }
 
-        fun title(title: String) = apply { this.title = title }
+        fun title(title: String): Builder = apply { this.title = title }
 
-        fun tags(tags: Array<String>) = apply { this.tags = tags }
+        fun tags(tags: Array<String>): Builder = apply { this.tags = tags }
 
-        fun deeplinks(deeplinks: Array<Map<String, String>>) = apply { this.deeplinks = deeplinks }
+        fun deeplinks(deeplinks: Array<Map<String, String>>): Builder = apply { this.deeplinks = deeplinks }
 
         /**
          * The long URL.
          */
-        fun longUrl(long_url: String) = apply { this.long_url = long_url }
+        fun longUrl(long_url: String): Builder = apply { this.long_url = long_url }
 
         /**
          * Returns the full JSON response if `true`.
          */
-        fun toJson(toJson: Boolean) = apply { this.toJson = toJson }
+        fun toJson(toJson: Boolean): Builder = apply { this.toJson = toJson }
 
         /**
          * Builds the configuration.
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 6e2aa83..13ec5f0 100644
--- a/src/main/kotlin/net/thauvin/erik/bitly/config/UpdateConfig.kt
+++ b/src/main/kotlin/net/thauvin/erik/bitly/config/UpdateConfig.kt
@@ -68,17 +68,17 @@ class UpdateConfig private constructor(builder: Builder) {
         /**
          * A Bitlink made of the domain and hash.
          */
-        fun bitlink(bitlink: String) = apply { this.bitlink = bitlink }
+        fun bitlink(bitlink: String): Builder = apply { this.bitlink = bitlink }
 
-        fun title(title: String) = apply { this.title = title }
-        fun archived(archived: Boolean) = apply { this.archived = archived }
-        fun tags(tags: Array<String>) = apply { this.tags = tags }
-        fun deepLinks(deepLinks: Array<Map<String, String>>) = apply { this.deeplinks = deepLinks }
+        fun title(title: String): Builder = apply { this.title = title }
+        fun archived(archived: Boolean): Builder = apply { this.archived = archived }
+        fun tags(tags: Array<String>): Builder = apply { this.tags = tags }
+        fun deepLinks(deepLinks: Array<Map<String, String>>): Builder = apply { this.deeplinks = deepLinks }
 
         /**
          * Returns the full JSON response if `true`.
          */
-        fun toJson(toJson: Boolean) = apply { this.toJson = toJson }
+        fun toJson(toJson: Boolean): Builder = apply { this.toJson = toJson }
 
         /**
          * Builds the configuration.