diff --git a/src/common/vc1.cpp b/src/common/vc1.cpp
index ab407684f..3839e8c57 100644
--- a/src/common/vc1.cpp
+++ b/src/common/vc1.cpp
@@ -54,6 +54,12 @@ vc1::frame_t::init() {
   contains_field           = false;
 }
 
+bool
+vc1::frame_t::is_key()
+  const {
+  return contains_sequence_header || (vc1::FRAME_TYPE_I == header.frame_type);
+}
+
 bool
 vc1::parse_sequence_header(const unsigned char *buf,
                            int size,
diff --git a/src/common/vc1.h b/src/common/vc1.h
index 71a482fa2..51e3b397d 100644
--- a/src/common/vc1.h
+++ b/src/common/vc1.h
@@ -119,6 +119,7 @@ struct frame_t {
 
   frame_t();
   void init();
+  bool is_key() const;
 };
 typedef std::shared_ptr<frame_t> frame_cptr;
 
diff --git a/src/output/p_vc1.cpp b/src/output/p_vc1.cpp
index 3a2473287..c68f7b95c 100644
--- a/src/output/p_vc1.cpp
+++ b/src/output/p_vc1.cpp
@@ -152,8 +152,7 @@ void
 vc1_video_packetizer_c::flush_frames() {
   while (m_parser.is_frame_available()) {
     vc1::frame_cptr frame = m_parser.get_frame();
-
-    add_packet(new packet_t(frame->data, frame->timecode, frame->duration, frame->contains_sequence_header ? -1 : m_previous_timecode));
+    add_packet(new packet_t(frame->data, frame->timecode, frame->duration, frame->is_key() ? -1 : m_previous_timecode));
 
     m_previous_timecode = frame->timecode;
   }
diff --git a/tests/results.txt b/tests/results.txt
index df050dc05..cee88762d 100644
--- a/tests/results.txt
+++ b/tests/results.txt
@@ -259,3 +259,4 @@ T_410extract_vp9:b6135380fa07f827384ad1004015d79c:passed:20131019-200643:0.03386
 T_411ui_locale_pt_PT:7378e1146862dcb96f11caa91d33c5cb-3182bfa8c7ef57b56185285fbd614c98:passed:20131026-154124:0.073196901
 T_412ui_locale_pl_PL:f84afd16653d395b33943ef722c63cfa-a4f512bdc00e1eab4d27a715174df149:passed:20131026-154845:0.077632905
 T_413memory_resize_nonfree_smaller:c1085152b4b60a197bf93d598d066924:passed:20131102-115507:0.066828215
+T_414vc1_no_sequence_headers_before_key_frames:48a03189f55b303a98332e6594f7bd31:passed:20131115-164756:0.133015738
diff --git a/tests/test-414vc1_no_sequence_headers_before_key_frames.rb b/tests/test-414vc1_no_sequence_headers_before_key_frames.rb
new file mode 100755
index 000000000..e25b4f2ea
--- /dev/null
+++ b/tests/test-414vc1_no_sequence_headers_before_key_frames.rb
@@ -0,0 +1,5 @@
+#!/usr/bin/ruby -w
+
+# T_414vc1_no_sequence_headers_before_key_frames
+describe "mkvmerge / VC1, no sequence headers before key frames"
+test_merge "data/mkv/vc1-no-sequence-headers-before-key-frames.mkv"