diff --git a/aegisub/video_context.cpp b/aegisub/video_context.cpp
index 07b711d247869fb0644f0e6e4a88a8a805b15fa8..41462436a9f998cbe3b3d42c3fb86c428413dba9 100644
--- a/aegisub/video_context.cpp
+++ b/aegisub/video_context.cpp
@@ -297,7 +297,7 @@ void VideoContext::SetVideo(const wxString &filename) {
 				keyFramesLoaded = true;
 #else
 #ifdef WITH_FFMPEG
-				LAVCKeyFrames k(filename);
+				LAVCKeyFrames k(filename.c_str());
 				KeyFrames = k.GetKeyFrames();
 				keyFramesLoaded = true;
 #endif