diff --git a/tests/benchmarks/multicore/idle_ppr/src/main.c b/tests/benchmarks/multicore/idle_ppr/src/main.c
index d91e386f235c..8afaee131f43 100644
--- a/tests/benchmarks/multicore/idle_ppr/src/main.c
+++ b/tests/benchmarks/multicore/idle_ppr/src/main.c
@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
  */
 #include <zephyr/kernel.h>
+#include <zephyr/cache.h>
 #include <zephyr/drivers/gpio.h>
 
 #include <zephyr/logging/log.h>
@@ -15,6 +16,11 @@ static const struct gpio_dt_spec led = GPIO_DT_SPEC_GET(DT_ALIAS(led0), gpios);
 static struct k_timer my_timer;
 static bool timer_expired;
 
+#define SHM_START_ADDR		(DT_REG_ADDR(DT_NODELABEL(cpuapp_cpurad_ipc_shm)))
+volatile static uint32_t *shared_var = (volatile uint32_t *) SHM_START_ADDR;
+#define APP_IS_READY	(1)
+#define RADIO_IS_READY	(2)
+
 void my_timer_handler(struct k_timer *dummy)
 {
 	timer_expired = true;
@@ -42,6 +48,40 @@ int main(void)
 
 	k_timer_init(&my_timer, my_timer_handler, NULL);
 
+	/* Synchronize all three cores.
+	 * APP indicates it's ready.
+	 * Radio waits for APP then indicates it's ready.
+	 * APP and PPR wait for RADIO.
+	 */
+#if defined(CONFIG_SOC_NRF54H20_CPUAPP)
+	LOG_DBG("APP starts");
+	/* Inform that APP is ready */
+	*shared_var = APP_IS_READY;
+	sys_cache_data_flush_range((void *) shared_var, sizeof(*shared_var));
+	LOG_DBG("APP wrote APP_IS_READY: %u", *shared_var);
+#elif defined(CONFIG_SOC_NRF54H20_CPURAD)
+	LOG_DBG("RADIO starts");
+	/* Wait until APP is ready */
+	while (*shared_var != APP_IS_READY) {
+		k_usleep(500);
+		sys_cache_data_invd_range((void *) shared_var, sizeof(*shared_var));
+		LOG_DBG("shared_var is: %u", *shared_var);
+	}
+	LOG_DBG("RADIO found that APP_IS_READY");
+	/* Inform that RADIO is ready */
+	*shared_var = RADIO_IS_READY;
+	sys_cache_data_flush_range((void *) shared_var, sizeof(*shared_var));
+	LOG_DBG("RADIO wrote RADIO_IS_READY: %u", *shared_var);
+	sys_cache_data_invd_range((void *) shared_var, sizeof(*shared_var));
+#endif
+	/* APP and PPR wait for RADIO */
+	while (*shared_var != RADIO_IS_READY) {
+		k_usleep(500);
+		sys_cache_data_invd_range((void *) shared_var, sizeof(*shared_var));
+		LOG_DBG("shared_var is: %u", *shared_var);
+	}
+	LOG_DBG("RADIO_IS_READY");
+
 	/* Run test forever */
 	while (1) {
 		timer_expired = false;