diff --git a/server/jellyfin/dto/dto.go b/server/jellyfin/dto/dto.go
index 97fdba4b9..f8c249f4e 100644
--- a/server/jellyfin/dto/dto.go
+++ b/server/jellyfin/dto/dto.go
@@ -179,20 +179,38 @@ type AuthenticationResult struct {
 	ServerId    string       `json:"ServerId"`
 }
 
+// MediaSourceInfo mirrors real Jellyfin's MediaSourceInfo object. Finamp's model declares several
+// of these bools and arrays as non-nullable, so a missing field deserializes as null and throws a
+// "type 'Null' is not a subtype of type 'bool'" cast error that aborts parsing of the whole item
+// list. They must always be emitted (no omitempty on bools) even when false/empty.
 type MediaSourceInfo struct {
-	Id                   string `json:"Id"`
-	Path                 string `json:"Path,omitempty"`
-	Protocol             string `json:"Protocol"`
-	Container            string `json:"Container,omitempty"`
-	Size                 int64  `json:"Size,omitempty"`
-	Name                 string `json:"Name,omitempty"`
-	IsRemote             bool   `json:"IsRemote"`
-	RunTimeTicks         int64  `json:"RunTimeTicks,omitempty"`
-	Bitrate              int    `json:"Bitrate,omitempty"`
-	SupportsTranscoding  bool   `json:"SupportsTranscoding"`
-	SupportsDirectStream bool   `json:"SupportsDirectStream"`
-	SupportsDirectPlay   bool   `json:"SupportsDirectPlay"`
-	Type                 string `json:"Type"`
+	Id                                  string   `json:"Id"`
+	Path                                string   `json:"Path,omitempty"`
+	Protocol                            string   `json:"Protocol"`
+	Container                           string   `json:"Container,omitempty"`
+	Size                                int64    `json:"Size,omitempty"`
+	Name                                string   `json:"Name,omitempty"`
+	IsRemote                            bool     `json:"IsRemote"`
+	RunTimeTicks                        int64    `json:"RunTimeTicks,omitempty"`
+	Bitrate                             int      `json:"Bitrate,omitempty"`
+	SupportsTranscoding                 bool     `json:"SupportsTranscoding"`
+	SupportsDirectStream                bool     `json:"SupportsDirectStream"`
+	SupportsDirectPlay                  bool     `json:"SupportsDirectPlay"`
+	Type                                string   `json:"Type"`
+	ReadAtNativeFramerate               bool     `json:"ReadAtNativeFramerate"`
+	IgnoreDts                           bool     `json:"IgnoreDts"`
+	IgnoreIndex                         bool     `json:"IgnoreIndex"`
+	GenPtsInput                         bool     `json:"GenPtsInput"`
+	IsInfiniteStream                    bool     `json:"IsInfiniteStream"`
+	UseMostCompatibleTranscodingProfile bool     `json:"UseMostCompatibleTranscodingProfile"`
+	RequiresOpening                     bool     `json:"RequiresOpening"`
+	RequiresClosing                     bool     `json:"RequiresClosing"`
+	RequiresLooping                     bool     `json:"RequiresLooping"`
+	SupportsProbing                     bool     `json:"SupportsProbing"`
+	HasSegments                         bool     `json:"HasSegments"`
+	MediaStreams                        []any    `json:"MediaStreams"`
+	MediaAttachments                    []any    `json:"MediaAttachments"`
+	Formats                             []string `json:"Formats"`
 }
 
 type PlaybackInfoResponse struct {
diff --git a/server/jellyfin/dto/mappers.go b/server/jellyfin/dto/mappers.go
index 4f62d3acd..4157b5c2c 100644
--- a/server/jellyfin/dto/mappers.go
+++ b/server/jellyfin/dto/mappers.go
@@ -26,6 +26,10 @@ func MediaSourceFromMediaFile(mf model.MediaFile) MediaSourceInfo {
 		SupportsDirectStream: true,
 		SupportsTranscoding:  true,
 		IsRemote:             false,
+		SupportsProbing:      true,
+		MediaStreams:         []any{},
+		MediaAttachments:     []any{},
+		Formats:              []string{},
 	}
 }
 
diff --git a/server/jellyfin/dto/mappers_test.go b/server/jellyfin/dto/mappers_test.go
index 1a63ed47c..53ac024e5 100644
--- a/server/jellyfin/dto/mappers_test.go
+++ b/server/jellyfin/dto/mappers_test.go
@@ -1,6 +1,7 @@
 package dto
 
 import (
+	"encoding/json"
 	"time"
 
 	"github.com/navidrome/navidrome/model"
@@ -44,6 +45,20 @@ var _ = Describe("mappers", func() {
 		Expect(src.SupportsDirectPlay).To(BeTrue())
 	})
 
+	It("serializes all Finamp-required MediaSourceInfo bools and arrays, never as null", func() {
+		mf := model.MediaFile{ID: "s1", Size: 5242880, Suffix: "mp3", BitRate: 320, Duration: 100}
+		src := MediaSourceFromMediaFile(mf)
+		b, err := json.Marshal(src)
+		Expect(err).ToNot(HaveOccurred())
+		j := string(b)
+		Expect(j).To(ContainSubstring(`"SupportsProbing":true`))
+		Expect(j).To(ContainSubstring(`"IsInfiniteStream":false`))
+		Expect(j).To(ContainSubstring(`"RequiresOpening":false`))
+		Expect(j).To(ContainSubstring(`"MediaStreams":[]`))
+		Expect(j).To(ContainSubstring(`"MediaAttachments":[]`))
+		Expect(j).To(ContainSubstring(`"Formats":[]`))
+	})
+
 	It("omits IndexNumber and ParentIndexNumber when track/disc numbers are untagged", func() {
 		mf := model.MediaFile{
 			ID: "song-2", Title: "Song", Album: "Alb", AlbumID: "alb-1",