diff --git a/boards/arm/stm32/nucleo-f4x1re/src/stm32_appinit.c b/boards/arm/stm32/nucleo-f4x1re/src/stm32_appinit.c
index 378624f052..6e447afc7e 100644
--- a/boards/arm/stm32/nucleo-f4x1re/src/stm32_appinit.c
+++ b/boards/arm/stm32/nucleo-f4x1re/src/stm32_appinit.c
@@ -45,6 +45,14 @@
 
 #include "nucleo-f4x1re.h"
 
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifndef OK
+#  define OK 0
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
diff --git a/boards/arm/stm32f0l0g0/nucleo-g070rb/src/stm32_appinit.c b/boards/arm/stm32f0l0g0/nucleo-g070rb/src/stm32_appinit.c
index 857ee20443..568e09bbb4 100644
--- a/boards/arm/stm32f0l0g0/nucleo-g070rb/src/stm32_appinit.c
+++ b/boards/arm/stm32f0l0g0/nucleo-g070rb/src/stm32_appinit.c
@@ -50,6 +50,14 @@
 
 #include "nucleo-g070rb.h"
 
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifndef OK
+#  define OK 0
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/