diff --git a/lib/capture/sp-capture-types.h b/lib/capture/sp-capture-types.h
index 8c169210..ed438665 100644
--- a/lib/capture/sp-capture-types.h
+++ b/lib/capture/sp-capture-types.h
@@ -184,7 +184,8 @@ typedef struct
 {
   SpCaptureFrame frame;
   gint64         duration;
-  gchar          name[32];
+  gchar          group[24];
+  gchar          name[40];
   gchar          message[0];
 } SpCaptureMark;
 
@@ -203,7 +204,7 @@ G_STATIC_ASSERT (sizeof (SpCaptureCounter) == 128);
 G_STATIC_ASSERT (sizeof (SpCaptureCounterValues) == 96);
 G_STATIC_ASSERT (sizeof (SpCaptureFrameCounterDefine) == 32);
 G_STATIC_ASSERT (sizeof (SpCaptureFrameCounterSet) == 32);
-G_STATIC_ASSERT (sizeof (SpCaptureMark) == 64);
+G_STATIC_ASSERT (sizeof (SpCaptureMark) == 96);
 
 static inline gint
 sp_capture_address_compare (SpCaptureAddress a,
diff --git a/lib/capture/sp-capture-writer.c b/lib/capture/sp-capture-writer.c
index 893b712c..a1fa2205 100644
--- a/lib/capture/sp-capture-writer.c
+++ b/lib/capture/sp-capture-writer.c
@@ -542,6 +542,7 @@ sp_capture_writer_add_mark (SpCaptureWriter *self,
                             gint             cpu,
                             GPid             pid,
                             guint64          duration,
+                            const gchar     *group,
                             const gchar     *name,
                             const gchar     *message)
 {
@@ -551,6 +552,7 @@ sp_capture_writer_add_mark (SpCaptureWriter *self,
 
   g_assert (self != NULL);
   g_assert (name != NULL);
+  g_assert (group != NULL);
 
   if (message == NULL)
     message = "";
@@ -569,7 +571,8 @@ sp_capture_writer_add_mark (SpCaptureWriter *self,
                                 SP_CAPTURE_FRAME_MARK);
 
   ev->duration = duration;
-  memcpy (ev->name, name, sizeof ev->name);
+  g_strlcpy (ev->group, group, sizeof ev->group);
+  g_strlcpy (ev->name, name, sizeof ev->name);
   memcpy (ev->message, message, message_len);
 
   self->stat.frame_count[SP_CAPTURE_FRAME_MARK]++;
diff --git a/lib/capture/sp-capture-writer.h b/lib/capture/sp-capture-writer.h
index 0c208e78..18670589 100644
--- a/lib/capture/sp-capture-writer.h
+++ b/lib/capture/sp-capture-writer.h
@@ -60,6 +60,7 @@ gboolean            sp_capture_writer_add_mark        (SpCaptureWriter         *
                                                        gint                     cpu,
                                                        GPid                     pid,
                                                        guint64                  duration,
+                                                       const gchar             *group,
                                                        const gchar             *name,
                                                        const gchar             *message);
 guint64             sp_capture_writer_add_jitmap      (SpCaptureWriter         *self,
diff --git a/tests/test-capture.c b/tests/test-capture.c
index ecc88ad5..4e348c16 100644
--- a/tests/test-capture.c
+++ b/tests/test-capture.c
@@ -543,8 +543,8 @@ test_reader_writer_mark (void)
 
   writer = sp_capture_writer_new ("mark1.syscap", 0);
 
-  sp_capture_writer_add_mark (writer, SP_CAPTURE_CURRENT_TIME, -1, -1, 125, "Draw", "hdmi-1");
-  sp_capture_writer_add_mark (writer, SP_CAPTURE_CURRENT_TIME, -1, -1, 0, "Deadline", "hdmi-1");
+  sp_capture_writer_add_mark (writer, SP_CAPTURE_CURRENT_TIME, -1, -1, 125, "thread-0", "Draw", "hdmi-1");
+  sp_capture_writer_add_mark (writer, SP_CAPTURE_CURRENT_TIME, -1, -1, 0, "thread-1", "Deadline", "hdmi-1");
 
   g_clear_pointer (&writer, sp_capture_writer_unref);
 
@@ -554,6 +554,7 @@ test_reader_writer_mark (void)
 
   mark = sp_capture_reader_read_mark (reader);
   g_assert_nonnull (mark);
+  g_assert_cmpstr (mark->group, ==, "thread-0");
   g_assert_cmpstr (mark->name, ==, "Draw");
   g_assert_cmpint (mark->duration, ==, 125);
   g_assert_cmpstr (mark->message, ==, "hdmi-1");
@@ -562,6 +563,7 @@ test_reader_writer_mark (void)
 
   mark = sp_capture_reader_read_mark (reader);
   g_assert_nonnull (mark);
+  g_assert_cmpstr (mark->group, ==, "thread-1");
   g_assert_cmpstr (mark->name, ==, "Deadline");
   g_assert_cmpint (mark->duration, ==, 0);
   g_assert_cmpstr (mark->message, ==, "hdmi-1");