diff --git a/drivers/include/drivers/interfaces/InterfaceDigitalInOut.h b/drivers/include/drivers/interfaces/InterfaceDigitalInOut.h
index a884784b5d..655c4bafcb 100644
--- a/drivers/include/drivers/interfaces/InterfaceDigitalInOut.h
+++ b/drivers/include/drivers/interfaces/InterfaceDigitalInOut.h
@@ -49,7 +49,8 @@ struct DigitalInOut {
         return *this;
     }
 
-    virtual DigitalInOut &operator= (DigitalInOut &rhs) {
+    virtual DigitalInOut &operator= (DigitalInOut &rhs)
+    {
         // Underlying implementation is responsible for thread-safety
         write(rhs.read());
         return *this;
diff --git a/drivers/include/drivers/interfaces/InterfaceDigitalOut.h b/drivers/include/drivers/interfaces/InterfaceDigitalOut.h
index 1ee1347423..deb0d14c23 100644
--- a/drivers/include/drivers/interfaces/InterfaceDigitalOut.h
+++ b/drivers/include/drivers/interfaces/InterfaceDigitalOut.h
@@ -46,7 +46,8 @@ struct DigitalOut {
         return *this;
     }
 
-    virtual DigitalOut &operator= (DigitalOut &rhs) {
+    virtual DigitalOut &operator= (DigitalOut &rhs)
+    {
         // Underlying implementation is responsible for thread-safety
         write(rhs.read());
         return *this;