diff --git a/CHANGES b/CHANGES
index 127b424c2..95fc56ce6 100644
--- a/CHANGES
+++ b/CHANGES
@@ -22,6 +22,7 @@ Misc:
  - Qt: Improved HiDPI support
  - Feature: Support ImageMagick 7
  - FFmpeg: Return false if a file fails to open
+ - FFmpeg: Force MP4 files to YUV420P
 
 0.5.2: (2016-12-31)
 Bugfixes:
diff --git a/src/feature/ffmpeg/ffmpeg-encoder.c b/src/feature/ffmpeg/ffmpeg-encoder.c
index d0374d46c..8ca67a7e2 100644
--- a/src/feature/ffmpeg/ffmpeg-encoder.c
+++ b/src/feature/ffmpeg/ffmpeg-encoder.c
@@ -304,6 +304,14 @@ bool FFmpegEncoderOpen(struct FFmpegEncoder* encoder, const char* outfile) {
 		}
 		av_opt_set(encoder->video->priv_data, "tune", "zerolatency", 0);
 	}
+
+	if (encoder->video->codec->id == AV_CODEC_ID_H264 &&
+	    (strcasecmp(encoder->containerFormat, "mp4") ||
+	        strcasecmp(encoder->containerFormat, "m4v") ||
+	        strcasecmp(encoder->containerFormat, "mov"))) {
+		// QuickTime and a few other things require YUV420
+		encoder->video->pix_fmt = AV_PIX_FMT_YUV420P;
+	}
 	avcodec_open2(encoder->video, vcodec, 0);
 #if LIBAVCODEC_VERSION_MAJOR >= 55
 	encoder->videoFrame = av_frame_alloc();