diff --git a/src/treebuilder/element-type.gperf b/src/treebuilder/element-type.gperf
index c0980d3..10b93da 100644
--- a/src/treebuilder/element-type.gperf
+++ b/src/treebuilder/element-type.gperf
@@ -110,6 +110,7 @@ s,                   S
 script,              SCRIPT
 select,              SELECT
 small,               SMALL
+source,              SOURCE
 spacer,              SPACER
 strike,              STRIKE
 strong,              STRONG
@@ -125,6 +126,7 @@ th,                  TH
 thead,               THEAD
 title,               TITLE
 tr,                  TR
+track,               TRACK
 tt,                  TT
 u,                   U
 ul,                  UL
diff --git a/src/treebuilder/element-type.h b/src/treebuilder/element-type.h
index 75612fd..02a396e 100644
--- a/src/treebuilder/element-type.h
+++ b/src/treebuilder/element-type.h
@@ -20,8 +20,8 @@ typedef enum
 	FORM, FRAME, FRAMESET, H1, H2, H3, H4, H5, H6, HEAD, HEADER, HR, IFRAME,
 	IMAGE, IMG, INPUT, ISINDEX, LI, LINK, LISTING, MAIN, MENU, META, NAV,
 	NOEMBED, NOFRAMES, NOSCRIPT, OL, OPTGROUP, OPTION, P, PARAM, PLAINTEXT,
-	PRE, SCRIPT, SECTION, SELECT, SPACER, STYLE, SUMMARY, TBODY, TEXTAREA,
-	TFOOT, THEAD, TITLE, TR, UL, WBR,
+	PRE, SCRIPT, SECTION, SELECT, SOURCE, SPACER, STYLE, SUMMARY, TBODY,
+	TEXTAREA, TFOOT, THEAD, TITLE, TR, TRACK, UL, WBR,
 /* Scoping */
 	APPLET, BUTTON, CAPTION, HTML, MARQUEE, OBJECT, TABLE, TD, TH,
 /* Formatting */
diff --git a/src/treebuilder/in_body.c b/src/treebuilder/in_body.c
index 0e4184c..765ea38 100644
--- a/src/treebuilder/in_body.c
+++ b/src/treebuilder/in_body.c
@@ -322,10 +322,11 @@ hubbub_error process_start_tag(hubbub_treebuilder *treebuilder,
 				current_table(treebuilder)].tainted = false;
 			treebuilder->context.mode = IN_TABLE;
 		}
-	} else if (type == AREA || type == BASEFONT || 
-			type == BGSOUND || type == BR || 
+	} else if (type == AREA || type == BASEFONT ||
+			type == BGSOUND || type == BR ||
 			type == EMBED || type == IMG || type == INPUT ||
-			type == PARAM || type == SPACER || type == WBR) {
+			type == PARAM || type == SOURCE || type == SPACER ||
+			type == TRACK || type == WBR) {
 		err = reconstruct_active_formatting_list(treebuilder);
 		if (err != HUBBUB_OK)
 			return err;