diff --git a/spm/cactus/cactus_def.h b/spm/cactus/cactus_def.h
index ef813d2..13b5dac 100644
--- a/spm/cactus/cactus_def.h
+++ b/spm/cactus/cactus_def.h
@@ -52,6 +52,8 @@
 #define CACTUS_PRINT_MAGIC		U(1)
 /* Return a magic number unique to Cactus */
 #define CACTUS_GET_MAGIC		U(2)
+/* Sleep for a number of milliseconds */
+#define CACTUS_SLEEP_MS			U(3)
 
 #define CACTUS_MAGIC_NUMBER		U(0x12481369)
 
diff --git a/spm/cactus/cactus_main.c b/spm/cactus/cactus_main.c
index bfbfa48..a062ef0 100644
--- a/spm/cactus/cactus_main.c
+++ b/spm/cactus/cactus_main.c
@@ -12,6 +12,7 @@
 #include <pl011.h>
 #include <plat_arm.h>
 #include <platform_def.h>
+#include <sp_helpers.h>
 #include <sprt_client.h>
 #include <sprt_svc.h>
 #include <std_svc.h>
@@ -70,6 +71,11 @@
 			ret0 = SPRT_SUCCESS;
 			break;
 
+		case CACTUS_SLEEP_MS:
+			sp_sleep(message->args[2]);
+			ret0 = SPRT_SUCCESS;
+			break;
+
 		default:
 			NOTICE("Cactus: Unhandled Service ID 0x%x\n",
 			       (unsigned int)message->args[1]);
diff --git a/spm/common/sp_helpers.c b/spm/common/sp_helpers.c
index cccaf8b..5aec977 100644
--- a/spm/common/sp_helpers.c
+++ b/spm/common/sp_helpers.c
@@ -55,17 +55,15 @@
 	INFO("Test \"%s\" passed.\n", test_desc);
 }
 
-void sp_sleep(uint32_t duration_sec)
+void sp_sleep(uint32_t ms)
 {
-	uint32_t timer_freq = mmio_read_32(SYS_CNT_CONTROL_BASE + CNTFID_OFF);
-	VERBOSE("%s: Timer frequency = %u\n", __func__, timer_freq);
+	uint64_t timer_freq = mmio_read_32(SYS_CNT_CONTROL_BASE + CNTFID_OFF);
+	VERBOSE("%s: Timer frequency = %llu\n", __func__, timer_freq);
 
-	INFO("%s: Sleeping for %u seconds...\n", __func__, duration_sec);
+	VERBOSE("%s: Sleeping for %u milliseconds...\n", __func__, ms);
 	uint64_t time1 = mmio_read_64(SYS_CNT_READ_BASE);
 	volatile uint64_t time2 = time1;
-	while ((time2 - time1) < duration_sec * timer_freq) {
+	while ((time2 - time1) < ((ms * timer_freq) / 1000U)) {
 		time2 = mmio_read_64(SYS_CNT_READ_BASE);
 	}
-
-	INFO("%s: Done\n", __func__);
 }
diff --git a/spm/common/sp_helpers.h b/spm/common/sp_helpers.h
index ab6415d..fb2d8ac 100644
--- a/spm/common/sp_helpers.h
+++ b/spm/common/sp_helpers.h
@@ -55,7 +55,7 @@
 void announce_test_start(const char *test_desc);
 void announce_test_end(const char *test_desc);
 
-/* Sleep for at least 'duration_sec' seconds then return. */
-void sp_sleep(uint32_t duration_sec);
+/* Sleep for at least 'ms' milliseconds. */
+void sp_sleep(uint32_t ms);
 
 #endif /* SP_HELPERS_H */
diff --git a/spm/ivy/ivy_def.h b/spm/ivy/ivy_def.h
index 11eeacf..729c46d 100644
--- a/spm/ivy/ivy_def.h
+++ b/spm/ivy/ivy_def.h
@@ -41,6 +41,8 @@
 #define IVY_PRINT_MAGIC			U(1001)
 /* Return a magic number unique to IVY */
 #define IVY_GET_MAGIC			U(1002)
+/* Sleep for a number of milliseconds */
+#define IVY_SLEEP_MS			U(1003)
 
 #define IVY_MAGIC_NUMBER		U(0x97531842)
 
diff --git a/spm/ivy/ivy_main.c b/spm/ivy/ivy_main.c
index cd81e88..1f1c5e4 100644
--- a/spm/ivy/ivy_main.c
+++ b/spm/ivy/ivy_main.c
@@ -12,6 +12,7 @@
 #include <pl011.h>
 #include <plat_arm.h>
 #include <platform_def.h>
+#include <sp_helpers.h>
 #include <sprt_client.h>
 #include <sprt_svc.h>
 
@@ -64,6 +65,11 @@
 			ret0 = SPRT_SUCCESS;
 			break;
 
+		case IVY_SLEEP_MS:
+			sp_sleep(message->args[2]);
+			ret0 = SPRT_SUCCESS;
+			break;
+
 		default:
 			NOTICE("IVY: Unhandled Service ID 0x%x\n",
 			       (unsigned int)message->args[1]);