diff --git a/src/codecs/html/index.ts b/src/codecs/html/index.ts
index db8df4969..90a232ee0 100644
--- a/src/codecs/html/index.ts
+++ b/src/codecs/html/index.ts
@@ -8,7 +8,6 @@ import { getLogger } from '@stencila/logga'
 import stencila, {
   isA,
   isInlineContent,
-  markTypes,
   microdata,
   microdataItemtype,
   microdataProperty,
@@ -2357,9 +2356,9 @@ function encodeThematicBreak(): HTMLHRElement {
 /**
  * Decode an inline element e.g `<em>` to a `Mark` node e.g. `Emphasis`.
  */
-function decodeMark<Type extends keyof typeof markTypes>(
+function decodeMark(
   elem: HTMLElement,
-  type: Type
+  type: stencila.Mark['type']
 ): stencila.Mark {
   return { type, content: decodeInlineChildNodes(elem) }
 }
diff --git a/src/codecs/jats/index.ts b/src/codecs/jats/index.ts
index 272f78bab..c41b85e50 100644
--- a/src/codecs/jats/index.ts
+++ b/src/codecs/jats/index.ts
@@ -1792,10 +1792,10 @@ function populateBibrContent(rid: string, state: EncodeState): void {
  * Deocde a JATS `<italic>`, `<bold>` etc node as a Stencila `Mark` node
  * of `Type` e.g. `Strong`.
  */
-function decodeMark<Type extends keyof typeof stencila.markTypes>(
+function decodeMark(
   elem: xml.Element,
   state: DecodeState,
-  type: Type
+  type: stencila.Mark['type']
 ): stencila.Mark[] {
   return [
     {