diff --git a/lib/message.cc b/lib/message.cc
index 1e325e23..e0834f1c 100644
--- a/lib/message.cc
+++ b/lib/message.cc
@@ -37,6 +37,7 @@ struct _notmuch_message {
     char *filename;
     notmuch_message_file_t *message_file;
     notmuch_message_list_t *replies;
+    unsigned long flags;
 
     Xapian::Document doc;
 };
@@ -108,6 +109,7 @@ _notmuch_message_create (const void *talloc_owner,
     message->doc_id = doc_id;
 
     message->frozen = 0;
+    message->flags = 0;
 
     /* Each of these will be lazily created as needed. */
     message->message_id = NULL;
@@ -445,6 +447,23 @@ notmuch_message_get_filename (notmuch_message_t *message)
     return message->filename;
 }
 
+notmuch_bool_t
+notmuch_message_get_flag (notmuch_message_t *message,
+			  notmuch_message_flag_t flag)
+{
+    return message->flags & (1 << flag);
+}
+
+void
+notmuch_message_set_flag (notmuch_message_t *message,
+			  notmuch_message_flag_t flag, notmuch_bool_t enable)
+{
+    if (enable)
+	message->flags |= (1 << flag);
+    else
+	message->flags &= ~(1 << flag);
+}
+
 time_t
 notmuch_message_get_date (notmuch_message_t *message)
 {
diff --git a/lib/notmuch.h b/lib/notmuch.h
index 8bba442f..3974820c 100644
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -684,6 +684,21 @@ notmuch_message_get_replies (notmuch_message_t *message);
 const char *
 notmuch_message_get_filename (notmuch_message_t *message);
 
+/* Message flags */
+typedef enum _notmuch_message_flag {
+    NOTMUCH_MSG_FLAG_MATCHING_SEARCH,
+} notmuch_message_flag_t;
+
+/* Get a value of a flag for the email corresponding to 'message'. */
+notmuch_bool_t
+notmuch_message_get_flag (notmuch_message_t *message,
+			  notmuch_message_flag_t flag);
+
+/* Set a value of a flag for the email corresponding to 'message'. */
+void
+notmuch_message_set_flag (notmuch_message_t *message,
+			  notmuch_message_flag_t flag, notmuch_bool_t value);
+
 /* Get the date of 'message' as a time_t value.
  *
  * For the original textual representation of the Date header from the
diff --git a/lib/thread.cc b/lib/thread.cc
index 58d88c2d..9e4cb5c8 100644
--- a/lib/thread.cc
+++ b/lib/thread.cc
@@ -132,6 +132,7 @@ _thread_add_matched_message (notmuch_thread_t *thread,
 			     notmuch_message_t *message)
 {
     time_t date;
+    notmuch_message_t *hashed_message;
 
     date = notmuch_message_get_date (message);
 
@@ -142,6 +143,13 @@ _thread_add_matched_message (notmuch_thread_t *thread,
 	thread->newest = date;
 
     thread->matched_messages++;
+
+    if (g_hash_table_lookup_extended (thread->message_hash,
+			    notmuch_message_get_message_id (message), NULL,
+			    (void **) &hashed_message)) {
+	notmuch_message_set_flag (hashed_message,
+			NOTMUCH_MSG_FLAG_MATCHING_SEARCH, 1);
+    }
 }
 
 static void
diff --git a/notmuch-show.c b/notmuch-show.c
index edebacaa..f189e943 100644
--- a/notmuch-show.c
+++ b/notmuch-show.c
@@ -155,9 +155,10 @@ show_message (void *ctx, notmuch_message_t *message, int indent)
     const char *name, *value;
     unsigned int i;
 
-    printf ("\fmessage{ id:%s depth:%d filename:%s\n",
+    printf ("\fmessage{ id:%s depth:%d match:%d filename:%s\n",
 	    notmuch_message_get_message_id (message),
 	    indent,
+	    notmuch_message_get_flag (message, NOTMUCH_MSG_FLAG_MATCHING_SEARCH),
 	    notmuch_message_get_filename (message));
 
     printf ("\fheader{\n");