diff --git a/src/template/core.js b/src/template/core.js
index dd31fee7..f7c5b420 100644
--- a/src/template/core.js
+++ b/src/template/core.js
@@ -25,7 +25,7 @@ function createContents(parts) {
     tableMode =
       tableMode ||
       signature.match(
-        /<\s*(table|th|tr|td|thead|tbody|tfoot|caption|colgroup)([^<>]|"[^"]*"|'[^']*')*>\s*$/,
+        /<\s*(table|th|tr|td|thead|tbody|tfoot|caption|colgroup)(?=[\s>/])([^<>]|"[^"]*"|'[^']*')*>\s*$/,
       );
 
     signature +=
diff --git a/test/spec/html.js b/test/spec/html.js
index a3a43c1f..c647d6e5 100644
--- a/test/spec/html.js
+++ b/test/spec/html.js
@@ -839,6 +839,20 @@ describe("html:", () => {
       expect(fragment.children[0].querySelectorAll("td").length).toBe(4);
     });
 
+    it("should render custom elements with table tag prefix", () => {
+      define({ tag: "thead-element" });
+
+      const render = (value, className) => html`
+        <thead-element>${value}</thead-element>
+        <div class="${className}"></div>
+      `;
+
+      render("content", "test")(fragment);
+
+      expect(fragment.children[0].textContent).toBe("content");
+      expect(fragment.children[1].getAttribute("class")).toBe("test");
+    });
+
     it("should set single expression in <tr> element", () => {
       const render = html`
         <table>