diff --git a/include/arpa/inet.h b/include/arpa/inet.h
index e3ff44acac5..5295dee6dde 100644
--- a/include/arpa/inet.h
+++ b/include/arpa/inet.h
@@ -97,7 +97,16 @@ extern "C"
 #define EXTERN extern
 #endif
 
-/* Functions to convert between nost and network byte ordering */
+/* Functions to convert between host and network byte ordering.
+ *
+ * REVISIT:  Since network order is defined as big-endian, the following
+ * functions are equivalent to functions declared in endian.h:
+ *
+ *   htonl   htobe32
+ *   htons   htobe16
+ *   ntohl   be32toh
+ *   ntohs   be16toh
+ */
 
 uint32_t    ntohl(uint32_t nl);
 uint16_t    ntohs(uint16_t ns);
diff --git a/include/sys/param.h b/include/sys/param.h
new file mode 100644
index 00000000000..9e2cac38419
--- /dev/null
+++ b/include/sys/param.h
@@ -0,0 +1,55 @@
+/****************************************************************************
+ * include/sys/param.h
+ *
+ *   Copyright (C) 2018 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_SYS_PARAM_H
+#define __INCLUDE_SYS_PARAM_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Type Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#endif /* __INCLUDE_SYS_PARAM_H */