diff --git a/carddav/server.go b/carddav/server.go
index e4bfaaa..572ebcb 100644
--- a/carddav/server.go
+++ b/carddav/server.go
@@ -261,6 +261,10 @@ func (b *backend) propfindAddressObject(propfind *internal.Propfind, ao *Address
 	return internal.NewPropfindResponse(ao.Href, propfind, props)
 }
 
+func (b *backend) Proppatch(r *http.Request, update *internal.Propertyupdate) (*internal.Response, error) {
+	panic("TODO")
+}
+
 func (b *backend) Put(r *http.Request) error {
 	panic("TODO")
 }
diff --git a/internal/elements.go b/internal/elements.go
index 9256e1a..5f0b90c 100644
--- a/internal/elements.go
+++ b/internal/elements.go
@@ -335,3 +335,22 @@ type CurrentUserPrincipal struct {
 	Href            string    `xml:"href,omitempty"`
 	Unauthenticated *struct{} `xml:"unauthenticated,omitempty"`
 }
+
+// https://tools.ietf.org/html/rfc4918#section-14.19
+type Propertyupdate struct {
+	XMLName xml.Name `xml:"DAV: propertyupdate"`
+	Remove  []Remove `xml:"remove"`
+	Set     []Set    `xml:"set"`
+}
+
+// https://tools.ietf.org/html/rfc4918#section-14.23
+type Remove struct {
+	XMLName xml.Name `xml:"DAV: remove"`
+	Prop    Prop     `xml:"prop"`
+}
+
+// https://tools.ietf.org/html/rfc4918#section-14.26
+type Set struct {
+	XMLName xml.Name `xml:"DAV: set"`
+	Prop    Prop     `xml:"prop"`
+}
diff --git a/internal/server.go b/internal/server.go
index 04d25d9..7c48a63 100644
--- a/internal/server.go
+++ b/internal/server.go
@@ -77,6 +77,7 @@ type Backend interface {
 	Options(r *http.Request) ([]string, error)
 	HeadGet(w http.ResponseWriter, r *http.Request) error
 	Propfind(r *http.Request, pf *Propfind, depth Depth) (*Multistatus, error)
+	Proppatch(r *http.Request, pu *Propertyupdate) (*Response, error)
 	Put(r *http.Request) error
 	Delete(r *http.Request) error
 	Mkcol(r *http.Request) error
@@ -112,6 +113,8 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			}
 		case "PROPFIND":
 			err = h.handlePropfind(w, r)
+		case "PROPPATCH":
+			err = h.handleProppatch(w, r)
 		case "MKCOL":
 			err = h.Backend.Mkcol(r)
 			if err == nil {
@@ -236,3 +239,18 @@ func NewPropfindResponse(href string, propfind *Propfind, props map[xml.Name]Pro
 
 	return resp, nil
 }
+
+func (h *Handler) handleProppatch(w http.ResponseWriter, r *http.Request) error {
+	var update Propertyupdate
+	if err := DecodeXMLRequest(r, &update); err != nil {
+		return err
+	}
+
+	resp, err := h.Backend.Proppatch(r, &update)
+	if err != nil {
+		return err
+	}
+
+	ms := NewMultistatus(*resp)
+	return ServeMultistatus(w, ms)
+}
diff --git a/server.go b/server.go
index 39778f0..afb5753 100644
--- a/server.go
+++ b/server.go
@@ -185,6 +185,11 @@ func (b *backend) propfindFile(propfind *internal.Propfind, fi *FileInfo) (*inte
 	return internal.NewPropfindResponse(fi.Href, propfind, props)
 }
 
+func (b *backend) Proppatch(r *http.Request, update *internal.Propertyupdate) (*internal.Response, error) {
+	// TODO: return a failed Response instead
+	return nil, internal.HTTPErrorf(http.StatusForbidden, "webdav: PROPPATCH is unsupported")
+}
+
 func (b *backend) Put(r *http.Request) error {
 	wc, err := b.FileSystem.Create(r.URL.Path)
 	if err != nil {