diff --git a/src/main/scala/com/github/tototoshi/csv/CSVParser.scala b/src/main/scala/com/github/tototoshi/csv/CSVParser.scala
index d214c3c..26f65ad 100644
--- a/src/main/scala/com/github/tototoshi/csv/CSVParser.scala
+++ b/src/main/scala/com/github/tototoshi/csv/CSVParser.scala
@@ -31,13 +31,13 @@ object CSVParser {
   /**
    * {{{
    * scala> com.github.tototoshi.csv.CSVParser.parse("a,b,c", '\\', ',', '"')
-   * res0: Option[List[String]] = Some(List(a, b, c))
+   * res0: Option[Seq[String]] = Some(List(a, b, c))
    *
    * scala> com.github.tototoshi.csv.CSVParser.parse("\"a\",\"b\",\"c\"", '\\', ',', '"')
-   * res1: Option[List[String]] = Some(List(a, b, c))
+   * res1: Option[Seq[String]] = Some(List(a, b, c))
    * }}}
    */
-  def parse(input: String, escapeChar: Char, delimiter: Char, quoteChar: Char): Option[List[String]] = {
+  def parse(input: String, escapeChar: Char, delimiter: Char, quoteChar: Char): Option[Seq[String]] = {
     val buf: Array[Char] = input.toCharArray
     var fields: Vector[String] = Vector()
     var field = new StringBuilder
@@ -299,7 +299,7 @@ object CSVParser {
 
 class CSVParser(format: CSVFormat) extends Serializable {
 
-  def parseLine(input: String): Option[List[String]] = {
+  def parseLine(input: String): Option[Seq[String]] = {
     val parsedResult = CSVParser.parse(input, format.escapeChar, format.delimiter, format.quoteChar)
     if (parsedResult == Some(List("")) && format.treatEmptyLineAsNil) Some(Nil)
     else parsedResult
diff --git a/src/main/scala/com/github/tototoshi/csv/CSVReader.scala b/src/main/scala/com/github/tototoshi/csv/CSVReader.scala
index 8ccf34c..90d7186 100644
--- a/src/main/scala/com/github/tototoshi/csv/CSVReader.scala
+++ b/src/main/scala/com/github/tototoshi/csv/CSVReader.scala
@@ -25,10 +25,10 @@ class CSVReader protected (private val lineReader: LineReader)(implicit format:
 
   private val parser = new CSVParser(format)
 
-  def readNext(): Option[List[String]] = {
+  def readNext(): Option[Seq[String]] = {
 
     @scala.annotation.tailrec
-    def parseNext(lineReader: LineReader, leftOver: Option[String] = None): Option[List[String]] = {
+    def parseNext(lineReader: LineReader, leftOver: Option[String] = None): Option[Seq[String]] = {
 
       val nextLine = lineReader.readLineWithTerminator()
       if (nextLine == null) {
@@ -86,18 +86,18 @@ class CSVReader protected (private val lineReader: LineReader)(implicit format:
 
   def toStreamWithHeaders: Stream[Map[String, String]] = iteratorWithHeaders.toStream
 
-  def toStream: Stream[List[String]] =
+  def toStream: Stream[Seq[String]] =
     Stream.continually(readNext()).takeWhile(_.isDefined).map(_.get)
 
-  def all(): List[List[String]] = {
+  def all(): Seq[Seq[String]] = {
     toStream.toList
   }
 
-  def allWithHeaders(): List[Map[String, String]] = {
+  def allWithHeaders(): Seq[Map[String, String]] = {
     allWithOrderedHeaders._2
   }
 
-  def allWithOrderedHeaders(): (List[String], List[Map[String, String]]) = {
+  def allWithOrderedHeaders(): (Seq[String], Seq[Map[String, String]]) = {
     val headers = readNext()
     val data = headers.map(headers => {
       val lines = all()
diff --git a/src/test/scala/com/github/tototoshi/csv/CSVReaderSpec.scala b/src/test/scala/com/github/tototoshi/csv/CSVReaderSpec.scala
index 3d34ac5..46bbb69 100644
--- a/src/test/scala/com/github/tototoshi/csv/CSVReaderSpec.scala
+++ b/src/test/scala/com/github/tototoshi/csv/CSVReaderSpec.scala
@@ -13,7 +13,7 @@ class CSVReaderSpec extends FunSpec with Matchers with Using {
   describe("CSVReader") {
 
     it("should be constructed with java.io.File") {
-      var res: List[String] = Nil
+      var res: Seq[String] = Nil
       using(CSVReader.open(new File("src/test/resources/simple.csv"))) { reader =>
         reader foreach { fields =>
           res = res ++ fields
@@ -23,7 +23,7 @@ class CSVReaderSpec extends FunSpec with Matchers with Using {
     }
 
     it("should be constructed with filename") {
-      var res: List[String] = Nil
+      var res: Seq[String] = Nil
       using(CSVReader.open("src/test/resources/simple.csv")) { reader =>
         reader foreach { fields =>
           res = res ++ fields
@@ -83,7 +83,7 @@ class CSVReaderSpec extends FunSpec with Matchers with Using {
     }
 
     it("read simple CSV from file") {
-      var res: List[String] = Nil
+      var res: Seq[String] = Nil
       using(CSVReader.open(new FileReader("src/test/resources/simple.csv"))) { reader =>
         reader foreach { fields =>
           res = res ++ fields
@@ -94,7 +94,7 @@ class CSVReaderSpec extends FunSpec with Matchers with Using {
 
     it("read simple CSV string") {
       val csvString = "a,b,c\nd,e,f\n"
-      var res: List[String] = Nil
+      var res: Seq[String] = Nil
       using(CSVReader.open(new StringReader(csvString))) { reader =>
         reader foreach { fields =>
           res = res ++ fields
@@ -104,7 +104,7 @@ class CSVReaderSpec extends FunSpec with Matchers with Using {
     }
 
     it("issue #22") {
-      var res: List[String] = Nil
+      var res: Seq[String] = Nil
       using(CSVReader.open("src/test/resources/issue22.csv")) { reader =>
         reader foreach { fields =>
           res = res ++ fields
@@ -113,7 +113,7 @@ class CSVReaderSpec extends FunSpec with Matchers with Using {
     }
 
     it("issue #32") {
-      var res: List[String] = Nil
+      var res: Seq[String] = Nil
       using(CSVReader.open("src/test/resources/issue32.csv")(new DefaultCSVFormat {
         override val escapeChar: Char = '\\'
       })) { reader =>
@@ -124,7 +124,7 @@ class CSVReaderSpec extends FunSpec with Matchers with Using {
     }
 
     it("should read csv file whose escape char is backslash") {
-      var res: List[String] = Nil
+      var res: Seq[String] = Nil
       implicit val format = new DefaultCSVFormat {
         override val escapeChar: Char = '\\'
       }
@@ -137,7 +137,7 @@ class CSVReaderSpec extends FunSpec with Matchers with Using {
     }
 
     it("read simple CSV file with empty quoted fields") {
-      var res: List[String] = Nil
+      var res: Seq[String] = Nil
       using(CSVReader.open("src/test/resources/issue30.csv")) { reader =>
         reader foreach { fields =>
           res = res ++ fields
@@ -147,7 +147,7 @@ class CSVReaderSpec extends FunSpec with Matchers with Using {
     }
 
     it("should read a file starting with BOM") {
-      var res: List[String] = Nil
+      var res: Seq[String] = Nil
       using(CSVReader.open("src/test/resources/bom.csv")) { reader =>
         reader foreach { fields =>
           res = res ++ fields
@@ -165,7 +165,7 @@ class CSVReaderSpec extends FunSpec with Matchers with Using {
     }
 
     it("read CSV file including escaped fields") {
-      var res: List[String] = Nil
+      var res: Seq[String] = Nil
       using(CSVReader.open(new FileReader("src/test/resources/escape.csv"))) { reader =>
         reader foreach { fields =>
           res = res ++ fields
@@ -175,7 +175,7 @@ class CSVReaderSpec extends FunSpec with Matchers with Using {
     }
 
     it("should correctly parse fields with line breaks enclosed in double quotes") {
-      var res: List[Seq[String]] = Nil
+      var res: Seq[Seq[String]] = Nil
       using(CSVReader.open(new FileReader("src/test/resources/line-breaks.csv"))) { reader =>
         reader foreach { fields =>
           res = res :+ fields
@@ -187,10 +187,10 @@ class CSVReaderSpec extends FunSpec with Matchers with Using {
 
     it("read TSV from file") {
       implicit val format = new TSVFormat {}
-      var res: List[Seq[String]] = Nil
+      var res: Seq[Seq[String]] = Nil
       using(CSVReader.open(new FileReader("src/test/resources/simple.tsv"))(format)) { reader =>
         reader.foreach { fields =>
-          res = res ::: fields :: Nil
+          res = res :+ fields
         }
       }
       res(0) should be(List("a", "b", "c"))