diff --git a/Source/WebCore/platform/graphics/gstreamer/mse/MediaPlayerPrivateGStreamerMSE.cpp b/Source/WebCore/platform/graphics/gstreamer/mse/MediaPlayerPrivateGStreamerMSE.cpp
index 40f8a494a6c5..54a386742332 100644
--- a/Source/WebCore/platform/graphics/gstreamer/mse/MediaPlayerPrivateGStreamerMSE.cpp
+++ b/Source/WebCore/platform/graphics/gstreamer/mse/MediaPlayerPrivateGStreamerMSE.cpp
@@ -269,6 +269,7 @@ bool MediaPlayerPrivateGStreamerMSE::doSeek(const SeekTarget& target, float rate
     // This will also add support for fastSeek once done (see webkit.org/b/260607)
     if (!m_mediaSourcePrivate)
         return false;
+    m_mediaSourcePrivate->willSeek();
     m_mediaSourcePrivate->waitForTarget(target)->whenSettled(RunLoop::current(), [this, weakThis = ThreadSafeWeakPtr { *this }](auto&& result) {
         RefPtr self = weakThis.get();
         if (!self || !result)
diff --git a/Source/WebCore/platform/graphics/gstreamer/mse/MediaSourcePrivateGStreamer.cpp b/Source/WebCore/platform/graphics/gstreamer/mse/MediaSourcePrivateGStreamer.cpp
index 31f380833006..cf0f4d96ba5e 100644
--- a/Source/WebCore/platform/graphics/gstreamer/mse/MediaSourcePrivateGStreamer.cpp
+++ b/Source/WebCore/platform/graphics/gstreamer/mse/MediaSourcePrivateGStreamer.cpp
@@ -205,6 +205,12 @@ TrackID MediaSourcePrivateGStreamer::registerTrackId(TrackID preferredId)
     return assignedId;
 }
 
+void MediaSourcePrivateGStreamer::willSeek()
+{
+    for (auto* sourceBuffer : m_activeSourceBuffers)
+        downcast<SourceBufferPrivateGStreamer>(sourceBuffer)->willSeek();
+}
+
 bool MediaSourcePrivateGStreamer::unregisterTrackId(TrackID trackId)
 {
     ASSERT(isMainThread());
diff --git a/Source/WebCore/platform/graphics/gstreamer/mse/MediaSourcePrivateGStreamer.h b/Source/WebCore/platform/graphics/gstreamer/mse/MediaSourcePrivateGStreamer.h
index b639e29a8933..b5df57af8031 100644
--- a/Source/WebCore/platform/graphics/gstreamer/mse/MediaSourcePrivateGStreamer.h
+++ b/Source/WebCore/platform/graphics/gstreamer/mse/MediaSourcePrivateGStreamer.h
@@ -77,6 +77,8 @@ class MediaSourcePrivateGStreamer final : public MediaSourcePrivate
     TrackID registerTrackId(TrackID);
     bool unregisterTrackId(TrackID);
 
+    void willSeek();
+
 #if !RELEASE_LOG_DISABLED
     const Logger& logger() const final { return m_logger; }
     ASCIILiteral logClassName() const override { return "MediaSourcePrivateGStreamer"_s; }
diff --git a/Source/WebCore/platform/graphics/gstreamer/mse/SourceBufferPrivateGStreamer.cpp b/Source/WebCore/platform/graphics/gstreamer/mse/SourceBufferPrivateGStreamer.cpp
index 9ba00d6ad38c..e8a1392f00b0 100644
--- a/Source/WebCore/platform/graphics/gstreamer/mse/SourceBufferPrivateGStreamer.cpp
+++ b/Source/WebCore/platform/graphics/gstreamer/mse/SourceBufferPrivateGStreamer.cpp
@@ -403,6 +403,23 @@ size_t SourceBufferPrivateGStreamer::platformEvictionThreshold() const
     return evictionThreshold;
 }
 
+void SourceBufferPrivateGStreamer::willSeek()
+{
+    ALWAYS_LOG(LOGIDENTIFIER);
+    m_seeking = true;
+}
+
+bool SourceBufferPrivateGStreamer::isSeeking() const
+{
+    return m_seeking;
+}
+
+void SourceBufferPrivateGStreamer::seekToTime(const MediaTime& time)
+{
+    m_seeking = false;
+    SourceBufferPrivate::seekToTime(time);
+}
+
 #undef GST_CAT_DEFAULT
 
 } // namespace WebCore
diff --git a/Source/WebCore/platform/graphics/gstreamer/mse/SourceBufferPrivateGStreamer.h b/Source/WebCore/platform/graphics/gstreamer/mse/SourceBufferPrivateGStreamer.h
index f6cf62245dbf..e4bc07fe2f2a 100644
--- a/Source/WebCore/platform/graphics/gstreamer/mse/SourceBufferPrivateGStreamer.h
+++ b/Source/WebCore/platform/graphics/gstreamer/mse/SourceBufferPrivateGStreamer.h
@@ -96,6 +96,10 @@ class SourceBufferPrivateGStreamer final : public SourceBufferPrivate, public Ca
     size_t platformMaximumBufferSize() const override;
     size_t platformEvictionThreshold() const final;
 
+    void willSeek();
+    bool isSeeking() const final;
+    void seekToTime(const MediaTime&) final;
+
 private:
     friend class AppendPipeline;
 
@@ -109,6 +113,7 @@ class SourceBufferPrivateGStreamer final : public SourceBufferPrivate, public Ca
     std::unique_ptr<AppendPipeline> m_appendPipeline;
     StdUnorderedMap<TrackID, RefPtr<MediaSourceTrackGStreamer>> m_tracks;
     std::optional<MediaPromise::Producer> m_appendPromise;
+    bool m_seeking { false };
 
 #if !RELEASE_LOG_DISABLED
     Ref<const Logger> m_logger;