diff --git a/src/Parser.ts b/src/Parser.ts
index 8ab4d7c48..73f9c2f8d 100644
--- a/src/Parser.ts
+++ b/src/Parser.ts
@@ -9,58 +9,60 @@ const formTags = new Set([
     "datalist",
     "textarea",
 ]);
-
 const pTag = new Set(["p"]);
-
-const openImpliesClose: Record<string, Set<string>> = {
-    tr: new Set(["tr", "th", "td"]),
-    th: new Set(["th"]),
-    td: new Set(["thead", "th", "td"]),
-    body: new Set(["head", "link", "script"]),
-    li: new Set(["li"]),
-    p: pTag,
-    h1: pTag,
-    h2: pTag,
-    h3: pTag,
-    h4: pTag,
-    h5: pTag,
-    h6: pTag,
-    select: formTags,
-    input: formTags,
-    output: formTags,
-    button: formTags,
-    datalist: formTags,
-    textarea: formTags,
-    option: new Set(["option"]),
-    optgroup: new Set(["optgroup", "option"]),
-    dd: new Set(["dt", "dd"]),
-    dt: new Set(["dt", "dd"]),
-    address: pTag,
-    article: pTag,
-    aside: pTag,
-    blockquote: pTag,
-    details: pTag,
-    div: pTag,
-    dl: pTag,
-    fieldset: pTag,
-    figcaption: pTag,
-    figure: pTag,
-    footer: pTag,
-    form: pTag,
-    header: pTag,
-    hr: pTag,
-    main: pTag,
-    nav: pTag,
-    ol: pTag,
-    pre: pTag,
-    section: pTag,
-    table: pTag,
-    ul: pTag,
-    rt: new Set(["rt", "rp"]),
-    rp: new Set(["rt", "rp"]),
-    tbody: new Set(["thead", "tbody"]),
-    tfoot: new Set(["thead", "tbody"]),
-};
+const tableSectionTags = new Set(["thead", "tbody"]);
+const ddtTags = new Set(["dd", "dt"]);
+const rtpTags = new Set(["rt", "rp"]);
+
+const openImpliesClose = new Map<string, Set<string>>([
+    ["tr", new Set(["tr", "th", "td"])],
+    ["th", new Set(["th"])],
+    ["td", new Set(["thead", "th", "td"])],
+    ["body", new Set(["head", "link", "script"])],
+    ["li", new Set(["li"])],
+    ["p", pTag],
+    ["h1", pTag],
+    ["h2", pTag],
+    ["h3", pTag],
+    ["h4", pTag],
+    ["h5", pTag],
+    ["h6", pTag],
+    ["select", formTags],
+    ["input", formTags],
+    ["output", formTags],
+    ["button", formTags],
+    ["datalist", formTags],
+    ["textarea", formTags],
+    ["option", new Set(["option"])],
+    ["optgroup", new Set(["optgroup", "option"])],
+    ["dd", ddtTags],
+    ["dt", ddtTags],
+    ["address", pTag],
+    ["article", pTag],
+    ["aside", pTag],
+    ["blockquote", pTag],
+    ["details", pTag],
+    ["div", pTag],
+    ["dl", pTag],
+    ["fieldset", pTag],
+    ["figcaption", pTag],
+    ["figure", pTag],
+    ["footer", pTag],
+    ["form", pTag],
+    ["header", pTag],
+    ["hr", pTag],
+    ["main", pTag],
+    ["nav", pTag],
+    ["ol", pTag],
+    ["pre", pTag],
+    ["section", pTag],
+    ["table", pTag],
+    ["ul", pTag],
+    ["rt", rtpTags],
+    ["rp", rtpTags],
+    ["tbody", tableSectionTags],
+    ["tfoot", tableSectionTags],
+]);
 
 const voidElements = new Set([
     "area",
@@ -245,13 +247,14 @@ export class Parser {
             name = name.toLowerCase();
         }
         this.tagname = name;
-        if (
-            !this.options.xmlMode &&
-            Object.prototype.hasOwnProperty.call(openImpliesClose, name)
-        ) {
+
+        const impliesClose =
+            !this.options.xmlMode && openImpliesClose.get(name);
+
+        if (impliesClose) {
             while (
                 this.stack.length > 0 &&
-                openImpliesClose[name].has(this.stack[this.stack.length - 1])
+                impliesClose.has(this.stack[this.stack.length - 1])
             ) {
                 const el = this.stack.pop()!;
                 this.cbs.onclosetag?.(el);