diff --git a/src/core/lib/iomgr/tcp_posix.c b/src/core/lib/iomgr/tcp_posix.c
index 793147f..98a2afd 100644
--- a/src/core/lib/iomgr/tcp_posix.c
+++ b/src/core/lib/iomgr/tcp_posix.c
@@ -250,7 +250,7 @@
   msg.msg_name = NULL;
   msg.msg_namelen = 0;
   msg.msg_iov = iov;
-  msg.msg_iovlen = tcp->incoming_buffer->count;
+  msg.msg_iovlen = (msg_iovlen_type)tcp->incoming_buffer->count;
   msg.msg_control = NULL;
   msg.msg_controllen = 0;
   msg.msg_flags = 0;