diff --git a/drivers/event/opdl/Makefile b/drivers/event/opdl/Makefile
index a8aff2c..747ae5b 100644
--- a/drivers/event/opdl/Makefile
+++ b/drivers/event/opdl/Makefile
@@ -7,8 +7,6 @@ include $(RTE_SDK)/mk/rte.vars.mk
 LIB = librte_pmd_opdl_event.a
 
 # build flags
-CFLAGS += -std=c99
-CFLAGS += -D_XOPEN_SOURCE=600
 CFLAGS += -O3
 CFLAGS += $(WERROR_FLAGS)
 # for older GCC versions, allow us to initialize an event using
diff --git a/drivers/event/opdl/opdl_evdev.c b/drivers/event/opdl/opdl_evdev.c
index dcbf404..d5e2b60 100644
--- a/drivers/event/opdl/opdl_evdev.c
+++ b/drivers/event/opdl/opdl_evdev.c
@@ -288,7 +288,8 @@ opdl_queue_setup(struct rte_eventdev *dev,
 		}
 	}
 	/* Check if queue id has been setup already */
-	for (uint32_t i = 0; i < device->nb_q_md; i++) {
+	uint32_t i;
+	for (i = 0; i < device->nb_q_md; i++) {
 		if (device->q_md[i].ext_id == queue_id) {
 			PMD_DRV_LOG(ERR, "DEV_ID:[%02d] : "
 				     "queue id %u already setup\n",
@@ -390,8 +391,8 @@ opdl_dump(struct rte_eventdev *dev, FILE *f)
 
 	fprintf(f,
 		"\n\n -- RING STATISTICS --\n");
-
-	for (uint32_t i = 0; i < device->nb_opdls; i++)
+	uint32_t i;
+	for (i = 0; i < device->nb_opdls; i++)
 		opdl_ring_dump(device->opdl[i], f);
 
 	fprintf(f,
@@ -400,7 +401,7 @@ opdl_dump(struct rte_eventdev *dev, FILE *f)
 		"Av. Grant Size     Av. Cycles PP"
 		"      Empty DEQs   Non Empty DEQs   Pkts Processed\n");
 
-	for (uint32_t i = 0; i < device->max_port_nb; i++) {
+	for (i = 0; i < device->max_port_nb; i++) {
 		char queue_id[64];
 		char total_cyc[64];
 		const char *p_type;
diff --git a/drivers/event/opdl/opdl_evdev_init.c b/drivers/event/opdl/opdl_evdev_init.c
index c37d8bc..84ab258 100644
--- a/drivers/event/opdl/opdl_evdev_init.c
+++ b/drivers/event/opdl/opdl_evdev_init.c
@@ -314,8 +314,8 @@ static int opdl_add_deps(struct opdl_evdev *device,
 					     "Stages and dependents"
 					     " are not for same opdl ring",
 					     opdl_pmd_dev_id(device));
-				for (uint32_t k = 0;
-						k < device->nb_opdls; k++) {
+				uint32_t k;
+				for (k = 0; k < device->nb_opdls; k++) {
 					opdl_ring_dump(device->opdl[k],
 							stdout);
 				}
@@ -505,8 +505,9 @@ void
 destroy_queues_and_rings(struct rte_eventdev *dev)
 {
 	struct opdl_evdev *device = opdl_pmd_priv(dev);
+	uint32_t i;
 
-	for (uint32_t i = 0; i < device->nb_opdls; i++) {
+	for (i = 0; i < device->nb_opdls; i++) {
 		if (device->opdl[i])
 			opdl_ring_free(device->opdl[i]);
 	}
@@ -639,7 +640,8 @@ create_queues_and_rings(struct rte_eventdev *dev)
 				 OPDL_Q_POS_START,
 				 -1);
 
-		for (uint32_t i = 0; i < device->nb_q_md; i++) {
+		uint32_t i;
+		for (i = 0; i < device->nb_q_md; i++) {
 
 			/* Check */
 			if (!device->q_md[i].setup) {
@@ -702,7 +704,8 @@ initialise_all_other_ports(struct rte_eventdev *dev)
 
 	struct opdl_evdev *device = opdl_pmd_priv(dev);
 
-	for (uint32_t i = 0; i < device->nb_ports; i++) {
+	uint32_t i;
+	for (i = 0; i < device->nb_ports; i++) {
 		struct opdl_port *port = &device->ports[i];
 		struct opdl_queue *queue = &device->queue[port->queue_id];
 
@@ -827,7 +830,7 @@ initialise_all_other_ports(struct rte_eventdev *dev)
 	 * setup the last bit of stage md
 	 */
 	if (!err) {
-		for (uint32_t i = 0; i < device->nb_ports; i++) {
+		for (i = 0; i < device->nb_ports; i++) {
 			struct opdl_port *port = &device->ports[i];
 			struct opdl_queue *queue =
 				&device->queue[port->queue_id];
@@ -872,7 +875,8 @@ initialise_queue_zero_ports(struct rte_eventdev *dev)
 	struct opdl_evdev *device = opdl_pmd_priv(dev);
 
 	/* Assign queue zero and figure out how many Q0 ports we have */
-	for (uint32_t i = 0; i < device->nb_ports; i++) {
+	uint32_t i;
+	for (i = 0; i < device->nb_ports; i++) {
 		struct opdl_port *port = &device->ports[i];
 		if (port->queue_id == OPDL_INVALID_QID) {
 			port->queue_id = 0;
@@ -889,7 +893,7 @@ initialise_queue_zero_ports(struct rte_eventdev *dev)
 	if (stage_inst) {
 
 		/* Assign the new created input stage to all relevant ports */
-		for (uint32_t i = 0; i < device->nb_ports; i++) {
+		for (i = 0; i < device->nb_ports; i++) {
 			struct opdl_port *port = &device->ports[i];
 			if (port->queue_id == 0) {
 				queue = &device->queue[port->queue_id];
@@ -914,8 +918,9 @@ assign_internal_queue_ids(struct rte_eventdev *dev)
 {
 	int err = 0;
 	struct opdl_evdev *device = opdl_pmd_priv(dev);
+	uint32_t i;
 
-	for (uint32_t i = 0; i < device->nb_ports; i++) {
+	for (i = 0; i < device->nb_ports; i++) {
 		struct opdl_port *port = &device->ports[i];
 		if (port->external_qid != OPDL_INVALID_QID) {
 			port->queue_id =
diff --git a/drivers/event/opdl/opdl_evdev_xstats.c b/drivers/event/opdl/opdl_evdev_xstats.c
index 94dfeee..70b84d9 100644
--- a/drivers/event/opdl/opdl_evdev_xstats.c
+++ b/drivers/event/opdl/opdl_evdev_xstats.c
@@ -86,7 +86,8 @@ opdl_xstats_get_names(const struct rte_eventdev *dev,
 
 	uint32_t port_idx = queue_port_id * max_num_port_xstat;
 
-	for (uint32_t j = 0; j < max_num_port_xstat; j++) {
+	uint32_t j;
+	for (j = 0; j < max_num_port_xstat; j++) {
 
 		strcpy(xstats_names[j].name,
 				device->port_xstat[j + port_idx].stat.name);
@@ -121,7 +122,8 @@ opdl_xstats_get(const struct rte_eventdev *dev,
 	uint32_t p_start = queue_port_id * max_num_port_xstat;
 	uint32_t p_finish = p_start + max_num_port_xstat;
 
-	for (uint32_t i = 0; i < n; i++) {
+	uint32_t i;
+	for (i = 0; i < n; i++) {
 		if (ids[i] < p_start || ids[i] >= p_finish)
 			return -EINVAL;
 
@@ -142,7 +144,8 @@ opdl_xstats_get_by_name(const struct rte_eventdev *dev,
 
 	uint32_t max_index = device->max_port_nb * max_num_port_xstat;
 
-	for (uint32_t i = 0; i < max_index; i++) {
+	uint32_t i;
+	for (i = 0; i < max_index; i++) {
 
 		if (strncmp(name,
 			   device->port_xstat[i].stat.name,
diff --git a/drivers/event/opdl/opdl_test.c b/drivers/event/opdl/opdl_test.c
index 44a5cc5..13d4f6b 100644
--- a/drivers/event/opdl/opdl_test.c
+++ b/drivers/event/opdl/opdl_test.c
@@ -433,7 +433,8 @@ atomic_basic(struct test *t)
 				return -1;
 			}
 
-			for (int j = 0; j < 3; j++) {
+			int j;
+			for (j = 0; j < 3; j++) {
 				deq_ev[j].op = RTE_EVENT_OP_FORWARD;
 				deq_ev[j].queue_id = t->qid[1];
 			}
@@ -495,8 +496,9 @@ static int
 check_statistics(void)
 {
 	int num_ports = 3; /* Hard-coded for this app */
+	int i;
 
-	for (int i = 0; i < num_ports; i++) {
+	for (i = 0; i < num_ports; i++) {
 		int num_stats, num_stats_returned;
 
 		num_stats = rte_event_dev_xstats_names_get(0,
