diff --git a/.gitignore b/.gitignore
index 7b1a9b4..459daa7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,5 @@
 target/
-boot/
\ No newline at end of file
+boot/
+.DS_Store
+.idea
+.idea_modules
\ No newline at end of file
diff --git a/src/main/scala/S3.scala b/src/main/scala/S3.scala
index b5053d4..eec212a 100644
--- a/src/main/scala/S3.scala
+++ b/src/main/scala/S3.scala
@@ -68,7 +68,7 @@ object S3 {
       val amzHeaders = req.headers.filter {
         case (name, _) => name.toLowerCase.startsWith("x-amz")
       }.foldLeft(Map.empty[String, Set[String]]) { case (m, (name, value)) => 
-        m + (name -> (m(name) + value))
+        m + (name -> (m.getOrElse(name, Set.empty[String]) + value))
       }
       val d = new Date
       req <:< Map("Authorization" -> "AWS %s:%s".format(accessKey, sign(req.method, path, secretKey, d, contentType, contentMd5, amzHeaders)),
diff --git a/src/test/scala/S3Spec.scala b/src/test/scala/S3Spec.scala
index d23daa2..811943c 100644
--- a/src/test/scala/S3Spec.scala
+++ b/src/test/scala/S3Spec.scala
@@ -13,6 +13,14 @@ object S3Spec extends Specification {
 
   def shouldWeSkip_? = List(access_key, secret_key) must notContain(None).orSkip
 
+  def newTempFile = {
+    val testFile = File.createTempFile("s3specs","bin")
+    val writer = new FileWriter(testFile)
+    writer.write("testing")
+    writer.close
+    testFile
+  }
+
   "S3" should {
     "be able to create a bucket" in {
       shouldWeSkip_?
@@ -24,10 +32,7 @@ object S3Spec extends Specification {
     "be able to create a file" in {
       shouldWeSkip_?
 
-      val testFile = File.createTempFile("s3specs","bin")
-      val writer = new FileWriter(testFile)
-      writer.write("testing")
-      writer.close
+      val testFile = newTempFile
 
       val r = test / "testing.txt" <<< (testFile, "plain/text") <@ (access_key.get, secret_key.get)
       Http x (r as_str){
@@ -36,6 +41,15 @@ object S3Spec extends Specification {
         }
       }
     }
+    "be able to send x-amz headers" in {
+      shouldWeSkip_?
+      val testFile = newTempFile
+      val headers = Map("x-amz-meta-author" -> "john@doe.com")
+      val r = test / "testing.txt" <<< (testFile, "plain/text") <:< headers <@ (access_key.get, secret_key.get)
+      Http x (r as_str) {
+        case (code, _, _, _) => code must be_== (200)
+      }
+    }
     "be able to retrieve a file" in {
       shouldWeSkip_?
       Http x(test / "testing.txt" <@ (access_key.get, secret_key.get) as_str) {