diff --git a/vlib/clipboard/clipboard_linux.v b/vlib/clipboard/clipboard_linux.v
index 46a77b288c..b61120ca8b 100644
--- a/vlib/clipboard/clipboard_linux.v
+++ b/vlib/clipboard/clipboard_linux.v
@@ -126,7 +126,7 @@ fn new_x11_clipboard(selection atom_type) &Clipboard {
 	if !(selection in [.clipboard, .primary, .secondary]) {
 		panic("Wrong atom_type. Must be one of .primary, .secondary or .clipboard.")
 	}
-	
+
 	//init x11 thread support
 	status := XInitThreads()
 	if status == 0 {
@@ -184,7 +184,6 @@ fn (cb &Clipboard) take_ownership(){
 
 fn (cb mut Clipboard) set_text(text string) bool {
 	if cb.window == Window(C.None) {return false}
-	mut ret := false
 	cb.mutex.lock()
 	cb.text = text
 	cb.is_owner = true
@@ -202,10 +201,10 @@ fn (cb mut Clipboard) get_text() string {
 		return cb.text
 	}
 	cb.got_text = false
-	
+
 	//Request a list of possible conversions, if we're pasting.
 	XConvertSelection(cb.display, cb.selection, cb.get_atom(.targets), cb.selection, cb.window, C.CurrentTime)
-	
+
 	//wait for the text to arrive
 	mut retries := 5
 	for {
@@ -260,7 +259,7 @@ fn (cb mut Clipboard) start_listener(){
 				if event.xselectionrequest.selection == cb.selection {
 					mut xsre := &XSelectionRequestEvent{}
 					xsre = &event.xselectionrequest
-					
+
 					mut xse := XSelectionEvent{
 						@type: C.SelectionNotify // 31
 						display: xsre.display
@@ -355,22 +354,22 @@ fn (cb &Clipboard) pick_target(prop Property) Atom {
 	else
 	{
 		atom_list := &Atom(prop.data)
-		
+
 		mut to_be_requested := Atom(0)
 
 		//This is higher than the maximum priority.
 		mut priority := math.max_i32
-		
+
 		supported_targets := cb.get_supported_targets()
 
 		for i := 0; i < prop.nitems; i++ {
 			//See if this data type is allowed and of higher priority (closer to zero)
 			//than the present one.
-			
+
 			if cb.is_supported_target(atom_list[i]) {
 				index := cb.get_target_index(atom_list[i])
 				if(priority > index && index >= 0)
-				{	
+				{
 					priority = index
 					to_be_requested = atom_list[i]
 				}
@@ -383,7 +382,7 @@ fn (cb &Clipboard) pick_target(prop Property) Atom {
 fn (cb &Clipboard) get_atoms(types ...atom_type) []Atom {
 	mut atoms := []Atom
 	for typ in types {
-		atoms << cb.atoms[typ]		
+		atoms << cb.atoms[typ]
 	}
 	return atoms
 }
diff --git a/vlib/encoding/base64/base64.v b/vlib/encoding/base64/base64.v
index 29f38a47e3..64e6a756f6 100644
--- a/vlib/encoding/base64/base64.v
+++ b/vlib/encoding/base64/base64.v
@@ -25,25 +25,25 @@ const (
  */
 pub fn decode(data string) string {
 	buffer := malloc( data.len * 3 / 4 )
-	return tos(buffer, decode_in_buffer(data, mut buffer) )
+	return tos(buffer, decode_in_buffer(data, buffer) )
 }
 
 /**
  * decode - expects a string. Returns its base64 encoded version.
  * @param data - the input string.
- * @return the base64 encoded version of the input string. 
+ * @return the base64 encoded version of the input string.
  * NB: base64 encoding returns a string that is ~ 4/3 larger than the input.
  * NB: if you need to encode many strings repeatedly, take a look at encode_in_buffer too.
  */
 pub fn encode(data string) string {
 	buffer := malloc( 4 * ((data.len + 2) / 3) )
-	return tos(buffer, encode_in_buffer(data, mut buffer))
+	return tos(buffer, encode_in_buffer(data, buffer))
 }
 
 /**
  * decode_in_buffer - expects a string reference, and a buffer in which to store its decoded version.
  * @param data - a reference/pointer to the input string that will be decoded.
- * @param buffer - a reference/pointer to the buffer that will hold the result. 
+ * @param buffer - a reference/pointer to the buffer that will hold the result.
  * The buffer should be large enough (i.e. 3/4 of the data.len, or larger) to hold the decoded data.
  * @return the actual size of the decoded data in the buffer.
  * NB: this function does NOT allocate new memory, and is suitable for handling very large strings.
@@ -104,12 +104,12 @@ pub fn decode_in_buffer(data &string, buffer byteptr) int {
 /**
  * encode_in_buffer - expects a string reference, and a buffer in which to store its base64 encoded version.
  * @param data - a reference/pointer to the input string.
- * @param buffer - a reference/pointer to the buffer that will hold the result. 
+ * @param buffer - a reference/pointer to the buffer that will hold the result.
  * The buffer should be large enough (i.e. 4/3 of the data.len, or larger) to hold the encoded data.
  * @return the actual size of the encoded data in the buffer.
  * NB: this function does NOT allocate new memory, and is suitable for handling very large strings.
  */
-pub fn encode_in_buffer(data &string, buffer mut byteptr) int {
+pub fn encode_in_buffer(data &string, buffer byteptr) int {
 	input_length := data.len
 	output_length := 4 * ((input_length + 2) / 3)
 
diff --git a/vlib/encoding/base64/base64_memory_test.v b/vlib/encoding/base64/base64_memory_test.v
index c7e71f1644..c33fba9b3d 100644
--- a/vlib/encoding/base64/base64_memory_test.v
+++ b/vlib/encoding/base64/base64_memory_test.v
@@ -3,26 +3,26 @@ import encoding.base64
 fn test_long_encoding(){
 	repeats := 1000
 	input_size := 3000
-	
+
 	s_original := 'a'.repeat(input_size)
 	s_encoded := base64.encode(s_original)
 	s_decoded := base64.decode(s_encoded)
-	
+
 	assert s_encoded.len > s_original.len
 	assert s_original == s_decoded
 
 	mut s := 0
-	
+
 	ebuffer := malloc( s_encoded.len )
 	for i := 0; i < repeats; i++ {
-		resultsize := base64.encode_in_buffer(s_original, mut ebuffer)
+		resultsize := base64.encode_in_buffer(s_original, ebuffer)
 		s += resultsize
 		assert resultsize == s_encoded.len
 	}
 
 	dbuffer := malloc( s_decoded.len )
 	for i := 0; i < repeats; i++ {
-		resultsize := base64.decode_in_buffer(s_encoded, mut dbuffer)
+		resultsize := base64.decode_in_buffer(s_encoded, dbuffer)
 		s += resultsize
 		assert resultsize == s_decoded.len
 	}