diff --git a/container/container.go b/container/container.go
index 42fdfd0a1b..6547a4ea0b 100644
--- a/container/container.go
+++ b/container/container.go
@@ -484,7 +484,9 @@ func copyEscapable(dst io.Writer, src io.ReadCloser, keys []byte) (written int64
 		nr, er := src.Read(buf)
 		if nr > 0 {
 			// ---- Docker addition
+			preservBuf := []byte{}
 			for i, key := range keys {
+				preservBuf = append(preservBuf, buf[0:nr]...)
 				if nr != 1 || buf[0] != key {
 					break
 				}
@@ -496,8 +498,15 @@ func copyEscapable(dst io.Writer, src io.ReadCloser, keys []byte) (written int64
 				}
 				nr, er = src.Read(buf)
 			}
-			// ---- End of docker
-			nw, ew := dst.Write(buf[0:nr])
+			var nw int
+			var ew error
+			if len(preservBuf) > 0 {
+				nw, ew = dst.Write(preservBuf)
+				nr = len(preservBuf)
+			} else {
+				// ---- End of docker
+				nw, ew = dst.Write(buf[0:nr])
+			}
 			if nw > 0 {
 				written += int64(nw)
 			}
diff --git a/integration-cli/docker_cli_run_unix_test.go b/integration-cli/docker_cli_run_unix_test.go
index 4872c2b909..9e03e3aa98 100644
--- a/integration-cli/docker_cli_run_unix_test.go
+++ b/integration-cli/docker_cli_run_unix_test.go
@@ -396,6 +396,55 @@ func (s *DockerSuite) TestRunAttachDetachKeysOverrideConfig(c *check.C) {
 	c.Assert(running, checker.Equals, "true", check.Commentf("expected container to still be running"))
 }
 
+func (s *DockerSuite) TestRunAttachInvalidDetachKeySequencePreserved(c *check.C) {
+	name := "attach-detach"
+	keyA := []byte{97}
+	keyB := []byte{98}
+
+	dockerCmd(c, "run", "--name", name, "-itd", "busybox", "cat")
+
+	cmd := exec.Command(dockerBinary, "attach", "--detach-keys='a,b,c'", name)
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		c.Fatal(err)
+	}
+	cpty, tty, err := pty.Open()
+	if err != nil {
+		c.Fatal(err)
+	}
+	defer cpty.Close()
+	cmd.Stdin = tty
+	if err := cmd.Start(); err != nil {
+		c.Fatal(err)
+	}
+	c.Assert(waitRun(name), check.IsNil)
+
+	// Invalid escape sequence aba, should print aba in output
+	if _, err := cpty.Write(keyA); err != nil {
+		c.Fatal(err)
+	}
+	time.Sleep(100 * time.Millisecond)
+	if _, err := cpty.Write(keyB); err != nil {
+		c.Fatal(err)
+	}
+	time.Sleep(100 * time.Millisecond)
+	if _, err := cpty.Write(keyA); err != nil {
+		c.Fatal(err)
+	}
+	time.Sleep(100 * time.Millisecond)
+	if _, err := cpty.Write([]byte("\n")); err != nil {
+		c.Fatal(err)
+	}
+
+	out, err := bufio.NewReader(stdout).ReadString('\n')
+	if err != nil {
+		c.Fatal(err)
+	}
+	if strings.TrimSpace(out) != "aba" {
+		c.Fatalf("expected 'aba', got %q", out)
+	}
+}
+
 // "test" should be printed
 func (s *DockerSuite) TestRunWithCPUQuota(c *check.C) {
 	testRequires(c, cpuCfsQuota)