diff --git a/go.mod b/go.mod
index 72c3e9e..4f41358 100644
--- a/go.mod
+++ b/go.mod
@@ -43,6 +43,7 @@ require (
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
 	github.com/jackc/puddle/v2 v2.2.1 // indirect
 	github.com/klauspost/compress v1.17.9 // indirect
+	github.com/ldez/mimetype v0.3.0 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
diff --git a/go.sum b/go.sum
index 9e0fe0d..da6162a 100644
--- a/go.sum
+++ b/go.sum
@@ -94,6 +94,8 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
 github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
+github.com/ldez/mimetype v0.3.0 h1:F4g3zubm207mB4I8wv9dBfcSMiIVUme7CQLz7ocx8hk=
+github.com/ldez/mimetype v0.3.0/go.mod h1:Lupzzb723ai7sMWfUuO6roX/jF48TiV22zVJrh3cGTc=
 github.com/leodido/go-urn v1.4.0 h1:WT9HwE9SGECu3lg4d/dIA+jxlljEa1/ffXKmRjqdmIQ=
 github.com/leodido/go-urn v1.4.0/go.mod h1:bvxc+MVxLKB4z00jd1z+Dvzr47oO32F/QSNjSBOlFxI=
 github.com/lib/pq v1.2.0 h1:LXpIM/LZ5xGFhOpXAQUIMM1HdyqzVYM13zNdjCEEcA0=
diff --git a/pkg/versia/utils/content_map.go b/pkg/versia/utils/content_map.go
index dd69385..3f58a8d 100644
--- a/pkg/versia/utils/content_map.go
+++ b/pkg/versia/utils/content_map.go
@@ -4,12 +4,12 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"slices"
+	"github.com/ldez/mimetype"
 )
 
 var (
-	validTextContentTypes  = []string{"text/html", "text/plain"}
-	validImageContentTypes = []string{"image/png", "image/jpeg", "image/gif", "image/svg+xml"}
+	preferredTextContentTypes  = []string{"text/html", "text/plain"}
+	preferredImageContentTypes = []string{"image/png", "image/jpeg", "image/gif", "image/svg+xml", "image/webp"}
 )
 
 // ContentMap is a map of content types to their respective content.
@@ -23,7 +23,7 @@ func (e UnexpectedContentTypeError) Error() string {
 	return fmt.Sprintf("unexpected content type: %s", e.MIMEType)
 }
 
-func (m ContentMap[T]) unmarshalJSON(raw []byte, valid []string) error {
+func (m ContentMap[T]) unmarshalJSON(raw []byte, mimetypeChecker func(type_ string) bool) error {
 	var cm map[string]json.RawMessage
 	if err := json.Unmarshal(raw, &cm); err != nil {
 		return err
@@ -33,11 +33,9 @@ func (m ContentMap[T]) unmarshalJSON(raw []byte, valid []string) error {
 
 	errs := make([]error, 0)
 	for k, v := range cm {
-		if valid != nil {
-			if !slices.Contains(valid, k) {
-				errs = append(errs, UnexpectedContentTypeError{k})
-				continue
-			}
+		if !mimetypeChecker(k) {
+			errs = append(errs, UnexpectedContentTypeError{k})
+			continue
 		}
 
 		var c T
@@ -76,11 +74,11 @@ type TextContent struct {
 type TextContentTypeMap ContentMap[TextContent]
 
 func (t TextContentTypeMap) UnmarshalJSON(data []byte) error {
-	return (ContentMap[TextContent])(t).unmarshalJSON(data, validTextContentTypes)
+	return (ContentMap[TextContent])(t).unmarshalJSON(data, mimetype.IsText)
 }
 
 func (t TextContentTypeMap) String() string {
-	if c := (ContentMap[TextContent])(t).getPreferred(validTextContentTypes); c != nil {
+	if c := (ContentMap[TextContent])(t).getPreferred(preferredImageContentTypes); c != nil {
 		return c.Content
 	}
 
@@ -116,11 +114,11 @@ type DataHash struct {
 type ImageContentMap ContentMap[File]
 
 func (i ImageContentMap) UnmarshalJSON(data []byte) error {
-	return (ContentMap[File])(i).unmarshalJSON(data, validImageContentTypes)
+	return (ContentMap[File])(i).unmarshalJSON(data, mimetype.IsImage)
 }
 
 func (i ImageContentMap) String() string {
-	if c := (ContentMap[File])(i).getPreferred(validImageContentTypes); c != nil {
+	if c := (ContentMap[File])(i).getPreferred(preferredImageContentTypes); c != nil {
 		return c.Content.String()
 	}
 
@@ -132,7 +130,9 @@ type NoteAttachmentContentMap ContentMap[File]
 var ErrContentMapEntryNotRemote = errors.New("content map entry not remote")
 
 func (i NoteAttachmentContentMap) UnmarshalJSON(data []byte) error {
-	if err := (ContentMap[File])(i).unmarshalJSON(data, nil); err != nil {
+	if err := (ContentMap[File])(i).unmarshalJSON(data, func(type_ string) bool {
+		return true
+	}); err != nil {
 		return err
 	}