diff --git a/hardware/arduino/avr/cores/arduino/WString.h b/hardware/arduino/avr/cores/arduino/WString.h
index b7d3852ba82..de5632c12c1 100644
--- a/hardware/arduino/avr/cores/arduino/WString.h
+++ b/hardware/arduino/avr/cores/arduino/WString.h
@@ -159,10 +159,12 @@ class String
 	char& operator [] (unsigned int index);
 	void getBytes(unsigned char *buf, unsigned int bufsize, unsigned int index=0) const;
 	void toCharArray(char *buf, unsigned int bufsize, unsigned int index=0) const
-		{getBytes((unsigned char *)buf, bufsize, index);}
-	const char * c_str() const { return buffer; }
-	const char* begin() { return c_str(); }
-	const char* end() { return c_str() + length(); }
+		{ getBytes((unsigned char *)buf, bufsize, index); }
+	const char* c_str() const { return buffer; }
+	char* begin() { return buffer; }
+	char* end() { return buffer + length(); }
+	const char* begin() const { return c_str(); }
+	const char* end() const { return c_str() + length(); }
 
 	// search
 	int indexOf( char ch ) const;
diff --git a/hardware/arduino/sam/cores/arduino/WString.h b/hardware/arduino/sam/cores/arduino/WString.h
index b7d3852ba82..86cd4c64ad5 100644
--- a/hardware/arduino/sam/cores/arduino/WString.h
+++ b/hardware/arduino/sam/cores/arduino/WString.h
@@ -161,8 +161,10 @@ class String
 	void toCharArray(char *buf, unsigned int bufsize, unsigned int index=0) const
 		{getBytes((unsigned char *)buf, bufsize, index);}
 	const char * c_str() const { return buffer; }
-	const char* begin() { return c_str(); }
-	const char* end() { return c_str() + length(); }
+ 	char* begin() { return buffer; }
+ 	char* end() { return buffer + length(); }
+ 	const char* begin() const { return c_str(); }
+ 	const char* end() const { return c_str() + length(); }
 
 	// search
 	int indexOf( char ch ) const;