diff --git a/src/util-utf8.scm b/src/util-utf8.scm
index 14a4c6b..0deef64 100644
--- a/src/util-utf8.scm
+++ b/src/util-utf8.scm
@@ -120,13 +120,13 @@ of the string and a list of remaining bytes (as integers).")
  (define/doc (utf8-bytes->lists chars)
    ("The same as above but accepts a list of bytes (as integers).")
    (let loop ((bytes chars)
-	      (rpending '())
+	      (rpending chars)
 	      (pending 0)
 	      (expected #f)
 	      (res '()))
      (if (null? bytes)
 	 (values (reverse res)
-		 (reverse rpending))
+		 rpending)
 	 (let ((byte (car bytes)))
 	   (cond (expected
 		  ;; Decode UTF-8 sequence
@@ -135,14 +135,14 @@ of the string and a list of remaining bytes (as integers).")
 			 (let ((char (integer->char (bitwise-ior pending
 								 (bitwise-and byte #b111111)))))
 			   (loop (cdr bytes)
-				 '()
+				 (cdr bytes)
 				 0
 				 #f
 				 (cons char res))))
 			(else
 			 ;; Intermediate bytes
 			 (loop (cdr bytes)
-			       (cons byte rpending)
+			       rpending
 			       (arithmetic-shift (bitwise-ior pending
 							      (bitwise-and byte #b111111)) 6)
 			       (sub1 expected)
@@ -152,7 +152,7 @@ of the string and a list of remaining bytes (as integers).")
 		  (cond ((= (bitwise-and byte #b10000000) 0)
 			 ;; ASCII
 			 (loop (cdr bytes)
-			       '()
+			       (cdr bytes)
 			       0
 			       #f
 			       (cons (integer->char byte) res)))
@@ -160,20 +160,20 @@ of the string and a list of remaining bytes (as integers).")
 			 ;; First byte of UTF-8 sequence
 			 (let-values
 			     (((first-byte char-bytes)
-			       (cond ((= (bitwise-and byte #b11000000) #b11000000)
+			       (cond ((= (bitwise-and byte #b11100000) #b11000000)
 				      (values (bitwise-and byte #b11111)
 					      2))
-				     ((= (bitwise-and byte #b11100000) #b11100000)
+				     ((= (bitwise-and byte #b11110000) #b11100000)
 				      (values (bitwise-and byte #b1111)
 					      3))
-				     ((= (bitwise-and byte #b11110000) #b11110000)
+				     ((= (bitwise-and byte #b11111000) #b11110000)
 				      (values (bitwise-and byte #b111)
 					      4))
 				     (else
 				      ;; Should not happen
 				      (values 0 0)))))
 			   (loop (cdr bytes)
-				 (list byte)
+				 bytes
 				 (arithmetic-shift first-byte 6)
 				 (sub1 char-bytes)
 				 res))))))))))