diff --git a/kernel/descriptor.cpp b/kernel/descriptor.cpp
index fb0933f3..2242e0d3 100644
--- a/kernel/descriptor.cpp
+++ b/kernel/descriptor.cpp
@@ -965,13 +965,19 @@ int Descriptor::poll(ioctx_t* ctx, PollNode* node)
 Ref<Descriptor> Descriptor::accept4(ioctx_t* ctx, uint8_t* addr,
                                     size_t* addrlen, int flags)
 {
+	if ( flags & ~(SOCK_NONBLOCK) )
+		return errno = EINVAL, Ref<Descriptor>();
+	int new_dflags = O_READ | O_WRITE;
+	if ( flags & SOCK_NONBLOCK )
+		new_dflags |= O_NONBLOCK;
+	flags &= ~(SOCK_NONBLOCK);
 	int old_ctx_dflags = ctx->dflags;
 	ctx->dflags = ContextFlags(old_ctx_dflags, dflags);
 	Ref<Vnode> retvnode = vnode->accept4(ctx, addr, addrlen, flags);
 	if ( !retvnode )
 		return Ref<Descriptor>();
 	ctx->dflags = old_ctx_dflags;
-	return Ref<Descriptor>(new Descriptor(retvnode, O_READ | O_WRITE));
+	return Ref<Descriptor>(new Descriptor(retvnode, new_dflags));
 }
 
 int Descriptor::bind(ioctx_t* ctx, const uint8_t* addr, size_t addrlen)
diff --git a/kernel/io.cpp b/kernel/io.cpp
index 8ac6bbce..aeb74518 100644
--- a/kernel/io.cpp
+++ b/kernel/io.cpp
@@ -731,15 +731,11 @@ int sys_accept4(int fd, void* addr, size_t* addrlen, int flags)
 	int fdflags = 0;
 	if ( flags & SOCK_CLOEXEC ) fdflags |= FD_CLOEXEC;
 	if ( flags & SOCK_CLOFORK ) fdflags |= FD_CLOFORK;
-	int descflags = 0;
-	if ( flags & SOCK_NONBLOCK ) descflags |= O_NONBLOCK;
-	flags &= ~(SOCK_CLOEXEC | SOCK_CLOFORK | SOCK_NONBLOCK);
+	flags &= ~(SOCK_CLOEXEC | SOCK_CLOFORK);
 	ioctx_t ctx; SetupUserIOCtx(&ctx);
 	Ref<Descriptor> conn = desc->accept4(&ctx, (uint8_t*) addr, addrlen, flags);
 	if ( !conn )
 		return -1;
-	if ( descflags )
-		conn->SetFlags(conn->GetFlags() | descflags);
 	return CurrentProcess()->GetDTable()->Allocate(conn, fdflags);
 }