diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-retrofit2/infrastructure/ApiClient.kt.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-retrofit2/infrastructure/ApiClient.kt.mustache
index 5026c3f0e07..d556f0e9869 100644
--- a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-retrofit2/infrastructure/ApiClient.kt.mustache
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-retrofit2/infrastructure/ApiClient.kt.mustache
@@ -287,8 +287,7 @@ import retrofit2.converter.moshi.MoshiConverterFactory
     }
 
     fun <S> createService(serviceClass: Class<S>): S {
-        var usedClient: OkHttpClient? = null
-        this.okHttpClient?.let { usedClient = it } ?: run {usedClient = clientBuilder.build()}
+        val usedClient = this.okHttpClient ?: clientBuilder.build()
         return retrofitBuilder.client(usedClient).build().create(serviceClass)
     }
 
@@ -313,4 +312,4 @@ import retrofit2.converter.moshi.MoshiConverterFactory
             System.getProperties().getProperty("{{packageName}}.baseUrl", "{{{basePath}}}")
         }
     }
-}
\ No newline at end of file
+}
diff --git a/samples/client/petstore/kotlin-retrofit2-rx3/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt b/samples/client/petstore/kotlin-retrofit2-rx3/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
index e3962e0c0f2..f23b3308a41 100644
--- a/samples/client/petstore/kotlin-retrofit2-rx3/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
+++ b/samples/client/petstore/kotlin-retrofit2-rx3/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
@@ -175,8 +175,7 @@ class ApiClient(
     }
 
     fun <S> createService(serviceClass: Class<S>): S {
-        var usedClient: OkHttpClient? = null
-        this.okHttpClient?.let { usedClient = it } ?: run {usedClient = clientBuilder.build()}
+        val usedClient = this.okHttpClient ?: clientBuilder.build()
         return retrofitBuilder.client(usedClient).build().create(serviceClass)
     }
 
@@ -201,4 +200,4 @@ class ApiClient(
             System.getProperties().getProperty("org.openapitools.client.baseUrl", "http://petstore.swagger.io/v2")
         }
     }
-}
\ No newline at end of file
+}
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
index 8f822585a6e..c8078936eb5 100644
--- a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
@@ -172,8 +172,7 @@ class ApiClient(
     }
 
     fun <S> createService(serviceClass: Class<S>): S {
-        var usedClient: OkHttpClient? = null
-        this.okHttpClient?.let { usedClient = it } ?: run {usedClient = clientBuilder.build()}
+        val usedClient = this.okHttpClient ?: clientBuilder.build()
         return retrofitBuilder.client(usedClient).build().create(serviceClass)
     }
 
@@ -198,4 +197,4 @@ class ApiClient(
             System.getProperties().getProperty("org.openapitools.client.baseUrl", "http://petstore.swagger.io/v2")
         }
     }
-}
\ No newline at end of file
+}