diff --git a/rtos/rtx/TARGET_CORTEX_A/rt_CMSIS.c b/rtos/rtx/TARGET_CORTEX_A/rt_CMSIS.c
index 5a132250a6..97218d0fec 100644
--- a/rtos/rtx/TARGET_CORTEX_A/rt_CMSIS.c
+++ b/rtos/rtx/TARGET_CORTEX_A/rt_CMSIS.c
@@ -905,7 +905,7 @@ uint8_t osThreadGetState (osThreadId thread_id) {
   if (__exceptional_mode()) return osErrorISR;     // Not allowed in ISR
 
   ptcb = rt_tid2ptcb(thread_id);                // Get TCB pointer
-  if (ptcb == NULL) return osErrorParameter;
+  if (ptcb == NULL) return INACTIVE;
 
   return ptcb->state;
 }
diff --git a/rtos/rtx/TARGET_CORTEX_M/rt_CMSIS.c b/rtos/rtx/TARGET_CORTEX_M/rt_CMSIS.c
index 5e33684bce..98efed089a 100644
--- a/rtos/rtx/TARGET_CORTEX_M/rt_CMSIS.c
+++ b/rtos/rtx/TARGET_CORTEX_M/rt_CMSIS.c
@@ -842,7 +842,7 @@ uint8_t osThreadGetState (osThreadId thread_id) {
   if (__get_IPSR() != 0U) return osErrorISR;     // Not allowed in ISR
 
   ptcb = rt_tid2ptcb(thread_id);                // Get TCB pointer
-  if (ptcb == NULL) return osErrorParameter;
+  if (ptcb == NULL) return INACTIVE;
 
   return ptcb->state;
 }