diff --git a/stub/src/main/java/io/grpc/kotlin/ServerCalls.kt b/stub/src/main/java/io/grpc/kotlin/ServerCalls.kt
index d2b532b4..cada7bc9 100644
--- a/stub/src/main/java/io/grpc/kotlin/ServerCalls.kt
+++ b/stub/src/main/java/io/grpc/kotlin/ServerCalls.kt
@@ -265,7 +265,9 @@ object ServerCalls {
         else -> Status.fromThrowable(failure).withCause(failure)
       }
       val trailers = failure?.let { Status.trailersFromThrowable(it) } ?: GrpcMetadata()
-      mutex.withLock { call.close(closeStatus, trailers) }
+      mutex.withLock {
+        if (!call.isCancelled) call.close(closeStatus, trailers)
+      }
     }
 
     return object: ServerCall.Listener<RequestT>() {