diff --git a/internal/containerupdate/docker_container_updater.go b/internal/containerupdate/docker_container_updater.go
index 4e0a1b7000..8dcb303586 100644
--- a/internal/containerupdate/docker_container_updater.go
+++ b/internal/containerupdate/docker_container_updater.go
@@ -40,16 +40,16 @@ func (cu *DockerUpdater) UpdateContainer(ctx context.Context, cInfo store.Contai
 		return errors.Wrap(err, "rmPathsFromContainer")
 	}
 
-	// TODO(maia): catch errors -- CopyToContainer doesn't return errors if e.g. it
-	// fails to write a file b/c of permissions =(
-	err = cu.dCli.CopyToContainerRoot(ctx, cInfo.ContainerID.String(), archiveToCopy)
+	err = cu.dCli.ExecInContainer(ctx, cInfo.ContainerID, model.Cmd{
+		Argv: []string{"tar", "-C", "/", "-x", "-f", "-"},
+	}, archiveToCopy, l.Writer(logger.InfoLvl))
 	if err != nil {
-		return err
+		return errors.Wrap(err, "copying files")
 	}
 
 	// Exec run's on container
 	for _, s := range cmds {
-		err = cu.dCli.ExecInContainer(ctx, cInfo.ContainerID, s, l.Writer(logger.InfoLvl))
+		err = cu.dCli.ExecInContainer(ctx, cInfo.ContainerID, s, nil, l.Writer(logger.InfoLvl))
 		if err != nil {
 			return build.WrapContainerExecError(err, cInfo.ContainerID, s)
 		}
@@ -75,7 +75,7 @@ func (cu *DockerUpdater) rmPathsFromContainer(ctx context.Context, cID container
 	}
 
 	out := bytes.NewBuffer(nil)
-	err := cu.dCli.ExecInContainer(ctx, cID, model.Cmd{Argv: makeRmCmd(paths)}, out)
+	err := cu.dCli.ExecInContainer(ctx, cID, model.Cmd{Argv: makeRmCmd(paths)}, nil, out)
 	if err != nil {
 		if docker.IsExitError(err) {
 			return fmt.Errorf("Error deleting files from container: %s", out.String())
diff --git a/internal/docker/client.go b/internal/docker/client.go
index da2d1e6127..50cf6901e5 100644
--- a/internal/docker/client.go
+++ b/internal/docker/client.go
@@ -82,11 +82,10 @@ type Client interface {
 	ContainerInspect(ctx context.Context, contianerID string) (types.ContainerJSON, error)
 	ContainerList(ctx context.Context, options types.ContainerListOptions) ([]types.Container, error)
 	ContainerRestartNoWait(ctx context.Context, containerID string) error
-	CopyToContainerRoot(ctx context.Context, container string, content io.Reader) error
 
 	// Execute a command in a container, streaming the command output to `out`.
 	// Returns an ExitError if the command exits with a non-zero exit code.
-	ExecInContainer(ctx context.Context, cID container.ID, cmd model.Cmd, out io.Writer) error
+	ExecInContainer(ctx context.Context, cID container.ID, cmd model.Cmd, in io.Reader, out io.Writer) error
 
 	ImagePush(ctx context.Context, image reference.NamedTagged) (io.ReadCloser, error)
 	ImageBuild(ctx context.Context, buildContext io.Reader, options BuildOptions) (types.ImageBuildResponse, error)
@@ -487,10 +486,6 @@ func (c *Cli) ImageBuild(ctx context.Context, buildContext io.Reader, options Bu
 	return response, err
 }
 
-func (c *Cli) CopyToContainerRoot(ctx context.Context, container string, content io.Reader) error {
-	return c.CopyToContainer(ctx, container, "/", content, types.CopyToContainerOptions{})
-}
-
 func (c *Cli) ContainerRestartNoWait(ctx context.Context, containerID string) error {
 
 	// Don't wait on the container to fully start.
@@ -499,13 +494,14 @@ func (c *Cli) ContainerRestartNoWait(ctx context.Context, containerID string) er
 	return c.ContainerRestart(ctx, containerID, &dur)
 }
 
-func (c *Cli) ExecInContainer(ctx context.Context, cID container.ID, cmd model.Cmd, out io.Writer) error {
-
+func (c *Cli) ExecInContainer(ctx context.Context, cID container.ID, cmd model.Cmd, in io.Reader, out io.Writer) error {
+	attachStdin := in != nil
 	cfg := types.ExecConfig{
 		Cmd:          cmd.Argv,
 		AttachStdout: true,
 		AttachStderr: true,
-		Tty:          true,
+		AttachStdin:  attachStdin,
+		Tty:          !attachStdin,
 	}
 
 	// ContainerExecCreate error-handling is awful, so before we Create
@@ -536,11 +532,30 @@ func (c *Cli) ExecInContainer(ctx context.Context, cID container.ID, cmd model.C
 		return errors.Wrap(err, "ExecInContainer#print")
 	}
 
+	inputDone := make(chan struct{})
+	if attachStdin {
+		go func() {
+			_, err := io.Copy(connection.Conn, in)
+			if err != nil {
+				logger.Get(ctx).Debugf("copy error: %v", err)
+			}
+			err = connection.CloseWrite()
+			if err != nil {
+				logger.Get(ctx).Debugf("close write error: %v", err)
+			}
+			close(inputDone)
+		}()
+	} else {
+		close(inputDone)
+	}
+
 	_, err = io.Copy(out, connection.Reader)
 	if err != nil {
 		return errors.Wrap(err, "ExecInContainer#copy")
 	}
 
+	<-inputDone
+
 	for {
 		inspected, err := c.ContainerExecInspect(ctx, execId.ID)
 		if err != nil {
diff --git a/internal/docker/exploding.go b/internal/docker/exploding.go
index 515a2e33e8..013bb9c5f2 100644
--- a/internal/docker/exploding.go
+++ b/internal/docker/exploding.go
@@ -47,10 +47,7 @@ func (c explodingClient) ContainerList(ctx context.Context, options types.Contai
 func (c explodingClient) ContainerRestartNoWait(ctx context.Context, containerID string) error {
 	return c.err
 }
-func (c explodingClient) CopyToContainerRoot(ctx context.Context, container string, content io.Reader) error {
-	return c.err
-}
-func (c explodingClient) ExecInContainer(ctx context.Context, cID container.ID, cmd model.Cmd, out io.Writer) error {
+func (c explodingClient) ExecInContainer(ctx context.Context, cID container.ID, cmd model.Cmd, in io.Reader, out io.Writer) error {
 	return c.err
 }
 func (c explodingClient) ImagePush(ctx context.Context, ref reference.NamedTagged) (io.ReadCloser, error) {
diff --git a/internal/docker/fake_client.go b/internal/docker/fake_client.go
index c6061fb2e0..960f8a4a4e 100644
--- a/internal/docker/fake_client.go
+++ b/internal/docker/fake_client.go
@@ -203,7 +203,14 @@ func (c *FakeClient) ContainerRestartNoWait(ctx context.Context, containerID str
 	return nil
 }
 
-func (c *FakeClient) ExecInContainer(ctx context.Context, cID container.ID, cmd model.Cmd, out io.Writer) error {
+func (c *FakeClient) ExecInContainer(ctx context.Context, cID container.ID, cmd model.Cmd, in io.Reader, out io.Writer) error {
+	if cmd.Argv[0] == "tar" {
+		c.CopyCount++
+		c.CopyContainer = string(cID)
+		c.CopyContent = in
+		return nil
+	}
+
 	execCall := ExecCall{
 		Container: cID.String(),
 		Cmd:       cmd,
@@ -221,13 +228,6 @@ func (c *FakeClient) ExecInContainer(ctx context.Context, cID container.ID, cmd
 	return err
 }
 
-func (c *FakeClient) CopyToContainerRoot(ctx context.Context, container string, content io.Reader) error {
-	c.CopyCount++
-	c.CopyContainer = container
-	c.CopyContent = content
-	return nil
-}
-
 func (c *FakeClient) ImagePush(ctx context.Context, ref reference.NamedTagged) (io.ReadCloser, error) {
 	c.PushCount++
 	c.PushImage = ref.String()
diff --git a/internal/docker/switch.go b/internal/docker/switch.go
index a22afbd5bc..69082c8b80 100644
--- a/internal/docker/switch.go
+++ b/internal/docker/switch.go
@@ -66,11 +66,8 @@ func (c *switchCli) ContainerList(ctx context.Context, options types.ContainerLi
 func (c *switchCli) ContainerRestartNoWait(ctx context.Context, containerID string) error {
 	return c.client().ContainerRestartNoWait(ctx, containerID)
 }
-func (c *switchCli) CopyToContainerRoot(ctx context.Context, container string, content io.Reader) error {
-	return c.client().CopyToContainerRoot(ctx, container, content)
-}
-func (c *switchCli) ExecInContainer(ctx context.Context, cID container.ID, cmd model.Cmd, out io.Writer) error {
-	return c.client().ExecInContainer(ctx, cID, cmd, out)
+func (c *switchCli) ExecInContainer(ctx context.Context, cID container.ID, cmd model.Cmd, in io.Reader, out io.Writer) error {
+	return c.client().ExecInContainer(ctx, cID, cmd, in, out)
 }
 func (c *switchCli) ImagePush(ctx context.Context, ref reference.NamedTagged) (io.ReadCloser, error) {
 	return c.client().ImagePush(ctx, ref)