diff --git a/aegisub/src/video_context.cpp b/aegisub/src/video_context.cpp
index 1b1036a3a..b6d68da47 100644
--- a/aegisub/src/video_context.cpp
+++ b/aegisub/src/video_context.cpp
@@ -434,13 +434,7 @@ void VideoContext::Stop() {
 	}
 }
 
-void VideoContext::OnPlayTimer(wxTimerEvent &event) {
-	// Lock
-	wxMutexError res = playMutex.TryLock();
-	if (res == wxMUTEX_BUSY) return;
-	playMutex.Unlock();
-	wxMutexLocker lock(playMutex);
-
+void VideoContext::OnPlayTimer(wxTimerEvent &) {
 	// Get time difference
 	int dif = playTime.Time();
 
diff --git a/aegisub/src/video_context.h b/aegisub/src/video_context.h
index 414b2c1d8..4dc8516c8 100644
--- a/aegisub/src/video_context.h
+++ b/aegisub/src/video_context.h
@@ -92,9 +92,6 @@ class VideoContext : public wxEvtHandler {
 	/// DOCME
 	wxString keyFramesFilename;
 
-	/// DOCME
-	wxMutex playMutex;
-
 	/// DOCME
 	wxTimer playback;