diff --git a/wolfssl/wolfcrypt/wc_port.h b/wolfssl/wolfcrypt/wc_port.h
index ee913ef50..710a2b230 100644
--- a/wolfssl/wolfcrypt/wc_port.h
+++ b/wolfssl/wolfcrypt/wc_port.h
@@ -69,6 +69,8 @@
     #include "kernel.h"
 #elif  defined(WOLFSSL_uTKERNEL2)
     #include "tk/tkernel.h"
+#elif defined(WOLFSSL_CMSIS_RTOS)
+    #include "cmsis_os.h"
 #elif defined(WOLFSSL_MDK_ARM)
     #if defined(WOLFSSL_MDK5)
         #include "cmsis_os.h"