diff --git a/rtos/rtx/TARGET_CORTEX_M/rt_HAL_CM.h b/rtos/rtx/TARGET_CORTEX_M/rt_HAL_CM.h
index d6bac9a0db2..c43a51b6af3 100644
--- a/rtos/rtx/TARGET_CORTEX_M/rt_HAL_CM.h
+++ b/rtos/rtx/TARGET_CORTEX_M/rt_HAL_CM.h
@@ -255,7 +255,11 @@ __inline static void rt_svc_init (void) {
   if (prigroup >= sh) {
     sh = prigroup + 1U;
   }
+
+/* Only change the SVCall priority if uVisor is not present. */
+#if !(defined(FEATURE_UVISOR) && defined(TARGET_UVISOR_SUPPORTED))
   NVIC_SYS_PRI2 = ((0xFEFFFFFFU << sh) & 0xFF000000U) | (NVIC_SYS_PRI2 & 0x00FFFFFFU);
+#endif /* !(defined(FEATURE_UVISOR) && defined(TARGET_UVISOR_SUPPORTED)) */
 #endif
 }