diff --git a/src/core/iomgr/tcp_server_posix.c b/src/core/iomgr/tcp_server_posix.c
index 5762eb8a9709136f78ab68f6113ce3740ca5a94f..e6c02186eea6da80f486ccaa9df1816059e41dab 100644
--- a/src/core/iomgr/tcp_server_posix.c
+++ b/src/core/iomgr/tcp_server_posix.c
@@ -252,7 +252,7 @@ static int add_socket_to_server(grpc_tcp_server *s, int fd,
     if (s->nports == s->port_capacity) {
       s->port_capacity *= 2;
       s->ports =
-          gpr_realloc(s->ports, sizeof(server_port *) * s->port_capacity);
+          gpr_realloc(s->ports, sizeof(server_port) * s->port_capacity);
     }
     sp = &s->ports[s->nports++];
     sp->server = s;