diff --git a/openai-java-client-okhttp/src/main/kotlin/com/openai/client/okhttp/OkHttpClient.kt b/openai-java-client-okhttp/src/main/kotlin/com/openai/client/okhttp/OkHttpClient.kt
index 8862168e..01fe5e8a 100644
--- a/openai-java-client-okhttp/src/main/kotlin/com/openai/client/okhttp/OkHttpClient.kt
+++ b/openai-java-client-okhttp/src/main/kotlin/com/openai/client/okhttp/OkHttpClient.kt
@@ -1,6 +1,7 @@
 package com.openai.client.okhttp
 
 import com.openai.core.RequestOptions
+import com.openai.core.checkRequired
 import com.openai.core.http.Headers
 import com.openai.core.http.HttpClient
 import com.openai.core.http.HttpMethod
@@ -192,7 +193,7 @@ private constructor(private val okHttpClient: okhttp3.OkHttpClient, private val
                     .callTimeout(if (timeout.seconds == 0L) timeout else timeout.plusSeconds(30))
                     .proxy(proxy)
                     .build(),
-                checkNotNull(baseUrl) { "`baseUrl` is required but was not set" },
+                checkRequired("baseUrl", baseUrl),
             )
     }
 }
diff --git a/openai-java-core/src/main/kotlin/com/openai/core/Check.kt b/openai-java-core/src/main/kotlin/com/openai/core/Check.kt
index 6c9f5e18..1ff8c724 100644
--- a/openai-java-core/src/main/kotlin/com/openai/core/Check.kt
+++ b/openai-java-core/src/main/kotlin/com/openai/core/Check.kt
@@ -2,8 +2,7 @@
 
 package com.openai.core
 
-@JvmSynthetic
-internal fun <T : Any> checkRequired(name: String, value: T?): T =
+fun <T : Any> checkRequired(name: String, value: T?): T =
     checkNotNull(value) { "`$name` is required, but was not set" }
 
 @JvmSynthetic
diff --git a/openai-java-core/src/main/kotlin/com/openai/core/http/HttpRequest.kt b/openai-java-core/src/main/kotlin/com/openai/core/http/HttpRequest.kt
index f83460af..2bafe110 100644
--- a/openai-java-core/src/main/kotlin/com/openai/core/http/HttpRequest.kt
+++ b/openai-java-core/src/main/kotlin/com/openai/core/http/HttpRequest.kt
@@ -1,5 +1,6 @@
 package com.openai.core.http
 
+import com.openai.core.checkRequired
 import com.openai.core.toImmutable
 
 class HttpRequest
@@ -134,7 +135,7 @@ private constructor(
 
         fun build(): HttpRequest =
             HttpRequest(
-                checkNotNull(method) { "`method` is required but was not set" },
+                checkRequired("method", method),
                 url,
                 pathSegments.toImmutable(),
                 headers.build(),
diff --git a/openai-java-core/src/main/kotlin/com/openai/core/http/RetryingHttpClient.kt b/openai-java-core/src/main/kotlin/com/openai/core/http/RetryingHttpClient.kt
index 5402fd52..a20fd1a5 100644
--- a/openai-java-core/src/main/kotlin/com/openai/core/http/RetryingHttpClient.kt
+++ b/openai-java-core/src/main/kotlin/com/openai/core/http/RetryingHttpClient.kt
@@ -1,6 +1,7 @@
 package com.openai.core.http
 
 import com.openai.core.RequestOptions
+import com.openai.core.checkRequired
 import com.openai.errors.OpenAIIoException
 import java.io.IOException
 import java.time.Clock
@@ -259,7 +260,7 @@ private constructor(
 
         fun build(): HttpClient =
             RetryingHttpClient(
-                checkNotNull(httpClient) { "`httpClient` is required but was not set" },
+                checkRequired("httpClient", httpClient),
                 clock,
                 maxRetries,
                 idempotencyHeader,