diff --git a/hardware/arduino/avr/cores/arduino/Print.cpp b/hardware/arduino/avr/cores/arduino/Print.cpp
index f6e499ba2..9a6b964d2 100644
--- a/hardware/arduino/avr/cores/arduino/Print.cpp
+++ b/hardware/arduino/avr/cores/arduino/Print.cpp
@@ -53,7 +53,7 @@ size_t Print::print(const __FlashStringHelper *ifsh)
 
 size_t Print::print(const String &s)
 {
-  return write(reinterpret_cast<const uint8_t*>(s.c_str()), s.length());
+  return write(s.c_str(), s.length());
 }
 
 size_t Print::print(const char str[])
diff --git a/hardware/arduino/sam/cores/arduino/Print.cpp b/hardware/arduino/sam/cores/arduino/Print.cpp
index 5e4810d55..23f6a2372 100644
--- a/hardware/arduino/sam/cores/arduino/Print.cpp
+++ b/hardware/arduino/sam/cores/arduino/Print.cpp
@@ -46,7 +46,7 @@ size_t Print::print(const __FlashStringHelper *ifsh)
 
 size_t Print::print(const String &s)
 {
-  return write(reinterpret_cast<const uint8_t*>(s.c_str()), s.length());
+  return write(s.c_str(), s.length());
 }
 
 size_t Print::print(const char str[])