diff --git a/aegisub/src/video_provider_ffmpegsource.cpp b/aegisub/src/video_provider_ffmpegsource.cpp
index ca010bc94..d783be86f 100644
--- a/aegisub/src/video_provider_ffmpegsource.cpp
+++ b/aegisub/src/video_provider_ffmpegsource.cpp
@@ -260,7 +260,7 @@ void FFmpegSourceVideoProvider::LoadVideo(wxString filename) {
 			KeyFramesList.Add(CurFrameNum);
 
 		// calculate timestamp and add to timecodes vector
-		int Timestamp = (int)((CurFrameData->DTS * TimeBase->Num) / TimeBase->Den);
+		int Timestamp = (int)((CurFrameData->PTS * TimeBase->Num) / TimeBase->Den);
 		TimecodesVector.push_back(Timestamp);
 	}
 	KeyFramesLoaded = true;