diff --git a/Source/WebCore/Modules/mediasource/MediaSource.cpp b/Source/WebCore/Modules/mediasource/MediaSource.cpp
index d8d8a4b10af9..76be64ef8bee 100644
--- a/Source/WebCore/Modules/mediasource/MediaSource.cpp
+++ b/Source/WebCore/Modules/mediasource/MediaSource.cpp
@@ -1201,6 +1201,7 @@ void MediaSource::detachFromElement()
         m_seekTargetPromise->reject(PlatformMediaError::Cancelled);
         m_seekTargetPromise.reset();
     }
+    m_pendingSeekTarget.reset();
 }
 
 void MediaSource::sourceBufferDidChangeActiveState(SourceBuffer&, bool)