diff --git a/lib/librte_cryptodev/rte_crypto.h b/lib/librte_cryptodev/rte_crypto.h
index 5bc3eaa..9019518 100644
--- a/lib/librte_cryptodev/rte_crypto.h
+++ b/lib/librte_cryptodev/rte_crypto.h
@@ -48,6 +48,7 @@ extern "C" {
 #include <rte_mbuf.h>
 #include <rte_memory.h>
 #include <rte_mempool.h>
+#include <rte_common.h>
 
 #include "rte_crypto_sym.h"
 
@@ -111,6 +112,7 @@ struct rte_crypto_op {
 	void *opaque_data;
 	/**< Opaque pointer for user data */
 
+	RTE_STD_C11
 	union {
 		struct rte_crypto_sym_op *sym;
 		/**< Symmetric operation parameters */
diff --git a/lib/librte_cryptodev/rte_crypto_sym.h b/lib/librte_cryptodev/rte_crypto_sym.h
index d9bd821..8178e5a 100644
--- a/lib/librte_cryptodev/rte_crypto_sym.h
+++ b/lib/librte_cryptodev/rte_crypto_sym.h
@@ -51,6 +51,7 @@ extern "C" {
 #include <rte_mbuf.h>
 #include <rte_memory.h>
 #include <rte_mempool.h>
+#include <rte_common.h>
 
 
 /** Symmetric Cipher Algorithms */
@@ -333,6 +334,7 @@ struct rte_crypto_sym_xform {
 	/**< next xform in chain */
 	enum rte_crypto_sym_xform_type type
 	; /**< xform type */
+	RTE_STD_C11
 	union {
 		struct rte_crypto_auth_xform auth;
 		/**< Authentication / hash xform */
@@ -371,6 +373,7 @@ struct rte_crypto_sym_op {
 
 	enum rte_crypto_sym_op_sess_type sess_type;
 
+	RTE_STD_C11
 	union {
 		struct rte_cryptodev_sym_session *session;
 		/**< Handle for the initialised session context */
diff --git a/lib/librte_cryptodev/rte_cryptodev.h b/lib/librte_cryptodev/rte_cryptodev.h
index 957bdd7..cf28541 100644
--- a/lib/librte_cryptodev/rte_cryptodev.h
+++ b/lib/librte_cryptodev/rte_cryptodev.h
@@ -48,6 +48,7 @@ extern "C" {
 #include "rte_kvargs.h"
 #include "rte_crypto.h"
 #include "rte_dev.h"
+#include <rte_common.h>
 
 #define CRYPTODEV_NAME_NULL_PMD		cryptodev_null_pmd
 /**< Null crypto PMD device name */
@@ -104,6 +105,7 @@ extern const char **rte_cyptodev_names;
 struct rte_cryptodev_symmetric_capability {
 	enum rte_crypto_sym_xform_type xform_type;
 	/**< Transform type : Authentication / Cipher */
+	RTE_STD_C11
 	union {
 		struct {
 			enum rte_crypto_auth_algorithm algo;
@@ -177,6 +179,7 @@ struct rte_cryptodev_capabilities {
 	enum rte_crypto_op_type op;
 	/**< Operation type */
 
+	RTE_STD_C11
 	union {
 		struct rte_cryptodev_symmetric_capability sym;
 		/**< Symmetric operation capability parameters */
@@ -751,6 +754,7 @@ rte_cryptodev_enqueue_burst(uint8_t dev_id, uint16_t qp_id,
 
 /** Cryptodev symmetric crypto session */
 struct rte_cryptodev_sym_session {
+	RTE_STD_C11
 	struct {
 		uint8_t dev_id;
 		/**< Device Id */
diff --git a/lib/librte_cryptodev/rte_cryptodev_pmd.h b/lib/librte_cryptodev/rte_cryptodev_pmd.h
index 42e7b79..a929ef1 100644
--- a/lib/librte_cryptodev/rte_cryptodev_pmd.h
+++ b/lib/librte_cryptodev/rte_cryptodev_pmd.h
@@ -52,6 +52,7 @@ extern "C" {
 #include <rte_mbuf.h>
 #include <rte_mempool.h>
 #include <rte_log.h>
+#include <rte_common.h>
 
 #include "rte_crypto.h"
 #include "rte_cryptodev.h"
@@ -65,6 +66,7 @@ extern "C" {
 #endif
 
 struct rte_cryptodev_session {
+	RTE_STD_C11
 	struct {
 		uint8_t dev_id;
 		enum rte_cryptodev_type type;
diff --git a/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h b/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
index 64beddf..8fa6fc6 100644
--- a/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
+++ b/lib/librte_eal/common/include/arch/ppc_64/rte_cycles.h
@@ -40,6 +40,7 @@ extern "C" {
 #include "generic/rte_cycles.h"
 
 #include <rte_byteorder.h>
+#include <rte_common.h>
 
 /**
  * Read the time base register.
@@ -52,6 +53,7 @@ rte_rdtsc(void)
 {
 	union {
 		uint64_t tsc_64;
+		RTE_STD_C11
 		struct {
 #if RTE_BYTE_ORDER == RTE_BIG_ENDIAN
 			uint32_t hi_32;
diff --git a/lib/librte_eal/common/include/arch/x86/rte_atomic_32.h b/lib/librte_eal/common/include/arch/x86/rte_atomic_32.h
index 400d8a9..5ce01b3 100644
--- a/lib/librte_eal/common/include/arch/x86/rte_atomic_32.h
+++ b/lib/librte_eal/common/include/arch/x86/rte_atomic_32.h
@@ -40,6 +40,8 @@
 #ifndef _RTE_ATOMIC_I686_H_
 #define _RTE_ATOMIC_I686_H_
 
+#include <rte_common.h>
+
 /*------------------------- 64 bit atomic operations -------------------------*/
 
 #ifndef RTE_FORCE_INTRINSICS
@@ -47,6 +49,7 @@ static inline int
 rte_atomic64_cmpset(volatile uint64_t *dst, uint64_t exp, uint64_t src)
 {
 	uint8_t res;
+	RTE_STD_C11
 	union {
 		struct {
 			uint32_t l32;
diff --git a/lib/librte_eal/common/include/arch/x86/rte_cycles.h b/lib/librte_eal/common/include/arch/x86/rte_cycles.h
index 6e3c7d8..5eb6ce9 100644
--- a/lib/librte_eal/common/include/arch/x86/rte_cycles.h
+++ b/lib/librte_eal/common/include/arch/x86/rte_cycles.h
@@ -75,12 +75,14 @@ extern "C" {
 extern int rte_cycles_vmware_tsc_map;
 #include <rte_branch_prediction.h>
 #endif
+#include <rte_common.h>
 
 static inline uint64_t
 rte_rdtsc(void)
 {
 	union {
 		uint64_t tsc_64;
+		RTE_STD_C11
 		struct {
 			uint32_t lo_32;
 			uint32_t hi_32;
diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index 477472b..98ecc1c 100644
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -59,6 +59,13 @@ extern "C" {
 #define asm __asm__
 #endif
 
+/** C extension macro for environments lacking C11 features. */
+#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
+#define RTE_STD_C11 __extension__
+#else
+#define RTE_STD_C11
+#endif
+
 #ifdef RTE_ARCH_STRICT_ALIGN
 typedef uint64_t unaligned_uint64_t __attribute__ ((aligned(1)));
 typedef uint32_t unaligned_uint32_t __attribute__ ((aligned(1)));
diff --git a/lib/librte_eal/common/include/rte_devargs.h b/lib/librte_eal/common/include/rte_devargs.h
index 53c59f5..c66895f 100644
--- a/lib/librte_eal/common/include/rte_devargs.h
+++ b/lib/librte_eal/common/include/rte_devargs.h
@@ -76,6 +76,7 @@ struct rte_devargs {
 	TAILQ_ENTRY(rte_devargs) next;
 	/** Type of device. */
 	enum rte_devtype type;
+	RTE_STD_C11
 	union {
 		/** Used if type is RTE_DEVTYPE_*_PCI. */
 		struct {
diff --git a/lib/librte_eal/common/include/rte_interrupts.h b/lib/librte_eal/common/include/rte_interrupts.h
index ff11ef3..fd3c6ef 100644
--- a/lib/librte_eal/common/include/rte_interrupts.h
+++ b/lib/librte_eal/common/include/rte_interrupts.h
@@ -34,6 +34,8 @@
 #ifndef _RTE_INTERRUPTS_H_
 #define _RTE_INTERRUPTS_H_
 
+#include <rte_common.h>
+
 /**
  * @file
  *
diff --git a/lib/librte_eal/common/include/rte_memory.h b/lib/librte_eal/common/include/rte_memory.h
index 12e0ebb..06b6596 100644
--- a/lib/librte_eal/common/include/rte_memory.h
+++ b/lib/librte_eal/common/include/rte_memory.h
@@ -104,6 +104,7 @@ typedef uint64_t phys_addr_t; /**< Physical address definition. */
  */
 struct rte_memseg {
 	phys_addr_t phys_addr;      /**< Start physical address. */
+	RTE_STD_C11
 	union {
 		void *addr;         /**< Start virtual address. */
 		uint64_t addr_64;   /**< Makes sure addr is always 64 bits */
diff --git a/lib/librte_eal/common/include/rte_memzone.h b/lib/librte_eal/common/include/rte_memzone.h
index dae98f5..8e42cae 100644
--- a/lib/librte_eal/common/include/rte_memzone.h
+++ b/lib/librte_eal/common/include/rte_memzone.h
@@ -53,6 +53,7 @@
 
 #include <stdio.h>
 #include <rte_memory.h>
+#include <rte_common.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -78,6 +79,7 @@ struct rte_memzone {
 	char name[RTE_MEMZONE_NAMESIZE];  /**< Name of the memory zone. */
 
 	phys_addr_t phys_addr;            /**< Start physical address. */
+	RTE_STD_C11
 	union {
 		void *addr;                   /**< Start virtual address. */
 		uint64_t addr_64;             /**< Makes sure addr is always 64-bits */
diff --git a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_interrupts.h b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_interrupts.h
index 3dacbff..d459bf4 100644
--- a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_interrupts.h
+++ b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_interrupts.h
@@ -82,6 +82,7 @@ struct rte_epoll_event {
 
 /** Handle for interrupts. */
 struct rte_intr_handle {
+	RTE_STD_C11
 	union {
 		int vfio_dev_fd;  /**< VFIO device file descriptor */
 		int uio_cfg_fd;  /**< UIO config file descriptor
diff --git a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h
index 2ef0506..164f127 100644
--- a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h
+++ b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h
@@ -61,6 +61,9 @@
 
 #ifdef __KERNEL__
 #include <linux/if.h>
+#define RTE_STD_C11
+#else
+#include <rte_common.h>
 #endif
 
 /**
@@ -85,6 +88,7 @@ enum rte_kni_req_id {
  */
 struct rte_kni_request {
 	uint32_t req_id;             /**< Request id */
+	RTE_STD_C11
 	union {
 		uint32_t new_mtu;    /**< New MTU */
 		uint8_t if_up;       /**< 1: interface up, 0: interface down */
diff --git a/lib/librte_hash/rte_thash.h b/lib/librte_hash/rte_thash.h
index d98e98e..a4886a8 100644
--- a/lib/librte_hash/rte_thash.h
+++ b/lib/librte_hash/rte_thash.h
@@ -54,6 +54,7 @@ extern "C" {
 #include <stdint.h>
 #include <rte_byteorder.h>
 #include <rte_ip.h>
+#include <rte_common.h>
 
 #ifdef __SSE3__
 #include <rte_vect.h>
@@ -102,6 +103,7 @@ static const __m128i rte_thash_ipv6_bswap_mask = {
 struct rte_ipv4_tuple {
 	uint32_t	src_addr;
 	uint32_t	dst_addr;
+	RTE_STD_C11
 	union {
 		struct {
 			uint16_t dport;
@@ -119,6 +121,7 @@ struct rte_ipv4_tuple {
 struct rte_ipv6_tuple {
 	uint8_t		src_addr[16];
 	uint8_t		dst_addr[16];
+	RTE_STD_C11
 	union {
 		struct {
 			uint16_t dport;
diff --git a/lib/librte_lpm/rte_lpm.h b/lib/librte_lpm/rte_lpm.h
index 28668a3..3ef4533 100644
--- a/lib/librte_lpm/rte_lpm.h
+++ b/lib/librte_lpm/rte_lpm.h
@@ -100,6 +100,7 @@ struct rte_lpm_tbl_entry_v20 {
 	 * a group index pointing to a tbl8 structure (tbl24 only, when
 	 * valid_group is set)
 	 */
+	RTE_STD_C11
 	union {
 		uint8_t next_hop;
 		uint8_t group_idx;
diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index c6cb299..23b7bf8 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -787,6 +787,7 @@ struct rte_mbuf {
 	 * or non-atomic) is controlled by the CONFIG_RTE_MBUF_REFCNT_ATOMIC
 	 * config option.
 	 */
+	RTE_STD_C11
 	union {
 		rte_atomic16_t refcnt_atomic; /**< Atomically accessed refcnt */
 		uint16_t refcnt;              /**< Non-atomically accessed refcnt */
@@ -806,6 +807,7 @@ struct rte_mbuf {
 	 * would have RTE_PTYPE_L2_ETHER and not RTE_PTYPE_L2_VLAN because the
 	 * vlan is stripped from the data.
 	 */
+	RTE_STD_C11
 	union {
 		uint32_t packet_type; /**< L2/L3/L4 and tunnel information. */
 		struct {
@@ -827,6 +829,7 @@ struct rte_mbuf {
 	union {
 		uint32_t rss;     /**< RSS hash result if RSS enabled */
 		struct {
+			RTE_STD_C11
 			union {
 				struct {
 					uint16_t hash;
@@ -854,6 +857,7 @@ struct rte_mbuf {
 	/* second cache line - fields only used in slow path or on TX */
 	MARKER cacheline1 __rte_cache_min_aligned;
 
+	RTE_STD_C11
 	union {
 		void *userdata;   /**< Can be used for external metadata */
 		uint64_t udata64; /**< Allow 8-byte userdata on 32-bit */
@@ -863,6 +867,7 @@ struct rte_mbuf {
 	struct rte_mbuf *next;    /**< Next segment of scattered packet. */
 
 	/* fields to support TX offloads */
+	RTE_STD_C11
 	union {
 		uint64_t tx_offload;       /**< combined for easy fetch */
 		__extension__
diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h
index 059ad9e..0243f9e 100644
--- a/lib/librte_mempool/rte_mempool.h
+++ b/lib/librte_mempool/rte_mempool.h
@@ -75,6 +75,7 @@
 #include <rte_branch_prediction.h>
 #include <rte_ring.h>
 #include <rte_memcpy.h>
+#include <rte_common.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -216,6 +217,7 @@ struct rte_mempool {
 	 * RTE_MEMPOOL_NAMESIZE next time the ABI changes
 	 */
 	char name[RTE_MEMZONE_NAMESIZE]; /**< Name of mempool. */
+	RTE_STD_C11
 	union {
 		void *pool_data;         /**< Ring or pool to store objects. */
 		uint64_t pool_id;        /**< External mempool identifier. */
diff --git a/lib/librte_pipeline/rte_pipeline.h b/lib/librte_pipeline/rte_pipeline.h
index b0b4615..f366348 100644
--- a/lib/librte_pipeline/rte_pipeline.h
+++ b/lib/librte_pipeline/rte_pipeline.h
@@ -87,6 +87,7 @@ extern "C" {
 
 #include <rte_port.h>
 #include <rte_table.h>
+#include <rte_common.h>
 
 struct rte_mbuf;
 
@@ -244,6 +245,7 @@ struct rte_pipeline_table_entry {
 	/** Reserved action */
 	enum rte_pipeline_action action;
 
+	RTE_STD_C11
 	union {
 		/** Output port ID (meta-data for "Send packet to output port"
 		action) */
diff --git a/lib/librte_timer/rte_timer.h b/lib/librte_timer/rte_timer.h
index 77547c6..a276a73 100644
--- a/lib/librte_timer/rte_timer.h
+++ b/lib/librte_timer/rte_timer.h
@@ -66,6 +66,7 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <stddef.h>
+#include <rte_common.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -91,6 +92,7 @@ enum rte_timer_type {
  * config) and an owner (the id of the lcore that owns the timer).
  */
 union rte_timer_status {
+	RTE_STD_C11
 	struct {
 		uint16_t state;  /**< Stop, pending, running, config. */
 		int16_t owner;   /**< The lcore that owns the timer. */
