diff --git a/targets/targets.json b/targets/targets.json
index 0a8549f009..05875546bf 100755
--- a/targets/targets.json
+++ b/targets/targets.json
@@ -1562,7 +1562,7 @@
         "macros": ["RTC_LSI=1"],
         "config": {
             "clock_source": {
-                "help": "Mask value : USE_PLL_HSE_EXTC | USE_PLL_HSE_XTAL (need HW patch) | USE_PLL_HSI",
+                "help": "Mask value : USE_PLL_HSE_EXTC (need HW patch) | USE_PLL_HSE_XTAL (need HW patch) | USE_PLL_HSI",
                 "value": "USE_PLL_HSI",
                 "macro_name": "CLOCK_SOURCE"
             }