diff --git a/hardware/arduino/avr/cores/arduino/WString.h b/hardware/arduino/avr/cores/arduino/WString.h
index 7335d4ed556..b7d3852ba82 100644
--- a/hardware/arduino/avr/cores/arduino/WString.h
+++ b/hardware/arduino/avr/cores/arduino/WString.h
@@ -81,7 +81,7 @@ class String
 	inline unsigned int length(void) const {return len;}
 
 	// creates a copy of the assigned value.  if the value is null or
-	// invalid, or if the memory allocation fails, the string will be 
+	// invalid, or if the memory allocation fails, the string will be
 	// marked as invalid ("if (s)" will be false).
 	String & operator = (const String &rhs);
 	String & operator = (const char *cstr);
@@ -92,10 +92,10 @@ class String
 	#endif
 
 	// concatenate (works w/ built-in types)
-	
+
 	// returns true on success, false on failure (in which case, the string
-	// is left unchanged).  if the argument is null or invalid, the 
-	// concatenation is considered unsucessful.  
+	// is left unchanged).  if the argument is null or invalid, the
+	// concatenation is considered unsucessful.
 	unsigned char concat(const String &str);
 	unsigned char concat(const char *cstr);
 	unsigned char concat(char c);
@@ -107,7 +107,7 @@ class String
 	unsigned char concat(float num);
 	unsigned char concat(double num);
 	unsigned char concat(const __FlashStringHelper * str);
-	
+
 	// if there's not enough memory for the concatenated value, the string
 	// will be left unchanged (but this isn't signalled in any way)
 	String & operator += (const String &rhs)	{concat(rhs); return (*this);}
@@ -162,7 +162,7 @@ class String
 		{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(); }	
+	const char* end() { 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 7335d4ed556..b7d3852ba82 100644
--- a/hardware/arduino/sam/cores/arduino/WString.h
+++ b/hardware/arduino/sam/cores/arduino/WString.h
@@ -81,7 +81,7 @@ class String
 	inline unsigned int length(void) const {return len;}
 
 	// creates a copy of the assigned value.  if the value is null or
-	// invalid, or if the memory allocation fails, the string will be 
+	// invalid, or if the memory allocation fails, the string will be
 	// marked as invalid ("if (s)" will be false).
 	String & operator = (const String &rhs);
 	String & operator = (const char *cstr);
@@ -92,10 +92,10 @@ class String
 	#endif
 
 	// concatenate (works w/ built-in types)
-	
+
 	// returns true on success, false on failure (in which case, the string
-	// is left unchanged).  if the argument is null or invalid, the 
-	// concatenation is considered unsucessful.  
+	// is left unchanged).  if the argument is null or invalid, the
+	// concatenation is considered unsucessful.
 	unsigned char concat(const String &str);
 	unsigned char concat(const char *cstr);
 	unsigned char concat(char c);
@@ -107,7 +107,7 @@ class String
 	unsigned char concat(float num);
 	unsigned char concat(double num);
 	unsigned char concat(const __FlashStringHelper * str);
-	
+
 	// if there's not enough memory for the concatenated value, the string
 	// will be left unchanged (but this isn't signalled in any way)
 	String & operator += (const String &rhs)	{concat(rhs); return (*this);}
@@ -162,7 +162,7 @@ class String
 		{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(); }	
+	const char* end() { return c_str() + length(); }
 
 	// search
 	int indexOf( char ch ) const;