diff --git a/Source/WebCore/platform/mediastream/RealtimeMediaSource.cpp b/Source/WebCore/platform/mediastream/RealtimeMediaSource.cpp
index 5ebc2b98ca639..935b8f8ee2bea 100644
--- a/Source/WebCore/platform/mediastream/RealtimeMediaSource.cpp
+++ b/Source/WebCore/platform/mediastream/RealtimeMediaSource.cpp
@@ -218,6 +218,25 @@ void RealtimeMediaSource::videoFrameAvailable(VideoFrame& videoFrame, VideoFrame
     updateHasStartedProducingData();
 
     Locker locker { m_videoFrameObserversLock };
+    if (m_videoFrameObservers.isEmpty()) {
+        if (m_pendingVideoFrames.size() < maxPendingVideoFramesBeforeAddTrack) {
+            m_pendingVideoFrames.append(PendingVideoFrame { &videoFrame, metadata });
+        }
+        else {
+            WTFLogAlways("RealtimeMediaSource: Dropping video frame (queue is full) %zu frames", m_pendingVideoFrames.size());
+        }
+        return;
+    }
+    if (!m_pendingVideoFrames.isEmpty()) {
+        WTFLogAlways("RealtimeMediaSource: Delivering %zu queued frame(s) (pipeline ready)", m_pendingVideoFrames.size());
+        for (auto& pending : m_pendingVideoFrames) {
+            if (pending.frame) {
+                for (auto* obs : m_videoFrameObservers)
+                    obs->videoFrameAvailable(*pending.frame, pending.metadata);
+            }
+        }
+        m_pendingVideoFrames.clear();
+    }
     for (auto* observer : m_videoFrameObservers)
         observer->videoFrameAvailable(videoFrame, metadata);
 }
diff --git a/Source/WebCore/platform/mediastream/RealtimeMediaSource.h b/Source/WebCore/platform/mediastream/RealtimeMediaSource.h
index 091aa0ead2afe..ffc3ad1007dc8 100644
--- a/Source/WebCore/platform/mediastream/RealtimeMediaSource.h
+++ b/Source/WebCore/platform/mediastream/RealtimeMediaSource.h
@@ -300,6 +300,13 @@ class WEBCORE_EXPORT RealtimeMediaSource
     mutable Lock m_videoFrameObserversLock;
     HashSet<VideoFrameObserver*> m_videoFrameObservers WTF_GUARDED_BY_LOCK(m_videoFrameObserversLock);
 
+    struct PendingVideoFrame {
+        RefPtr<VideoFrame> frame;
+        VideoFrameTimeMetadata metadata;
+    };
+    static constexpr size_t maxPendingVideoFramesBeforeAddTrack = 30;
+    Vector<PendingVideoFrame> m_pendingVideoFrames WTF_GUARDED_BY_LOCK(m_videoFrameObserversLock);
+
     // Set on the main thread from constraints.
     IntSize m_size;
     // Set on sample generation thread.