diff --git a/openai-java-core/src/main/kotlin/com/openai/helpers/ResponseAccumulator.kt b/openai-java-core/src/main/kotlin/com/openai/helpers/ResponseAccumulator.kt
index 0e7ee6365..63862ddf7 100644
--- a/openai-java-core/src/main/kotlin/com/openai/helpers/ResponseAccumulator.kt
+++ b/openai-java-core/src/main/kotlin/com/openai/helpers/ResponseAccumulator.kt
@@ -116,7 +116,13 @@ class ResponseAccumulator private constructor() {
      *   accumulated. A [ResponseAccumulator] can only be used to accumulate a single [Response].
      */
     fun accumulate(event: ResponseStreamEvent): ResponseStreamEvent {
-        check(response == null) { "Response has already been completed." }
+        // The API may send non-terminal events (e.g. `response.rate_limits.updated`) after a
+        // terminal event (`response.completed`, `response.failed`, `response.incomplete`).
+        // These events do not carry response data and are safe to ignore. Throwing here would
+        // break callers that pass every streamed event to the accumulator.
+        if (response != null) {
+            return event
+        }
 
         event.accept(
             object : ResponseStreamEvent.Visitor<Unit> {
diff --git a/openai-java-core/src/test/kotlin/com/openai/helpers/ResponseAccumulatorTest.kt b/openai-java-core/src/test/kotlin/com/openai/helpers/ResponseAccumulatorTest.kt
index 2b12569d7..6488c266a 100644
--- a/openai-java-core/src/test/kotlin/com/openai/helpers/ResponseAccumulatorTest.kt
+++ b/openai-java-core/src/test/kotlin/com/openai/helpers/ResponseAccumulatorTest.kt
@@ -62,16 +62,17 @@ internal class ResponseAccumulatorTest {
     }
 
     @Test
-    fun accumulateAfterCompleted() {
+    fun accumulateAfterCompletedIgnoresPostCompletionEvents() {
         val accumulator = ResponseAccumulator.create()
 
         accumulator.accumulate(ResponseStreamEvent.ofCompleted(responseCompletedEvent()))
 
-        assertThatThrownBy {
-                accumulator.accumulate(ResponseStreamEvent.ofCompleted(responseCompletedEvent()))
-            }
-            .isExactlyInstanceOf(IllegalStateException::class.java)
-            .hasMessage("Response has already been completed.")
+        // Post-completion events (e.g. `response.rate_limits.updated`) should be silently
+        // ignored rather than throwing. The original response should remain intact.
+        assertThatNoException().isThrownBy {
+            accumulator.accumulate(ResponseStreamEvent.ofCreated(responseCreatedEvent()))
+        }
+        assertThat(accumulator.response().id()).isEqualTo("response-id")
     }
 
     @Test