diff --git a/README.md b/README.md
index 0ea7468..276d37a 100644
--- a/README.md
+++ b/README.md
@@ -108,7 +108,7 @@ module.exports = {
 ## Customizing the Marko compiler
 
 You can override the default [Marko compiler options](https://markojs.com/docs/compiler/#options) by adding a Jest "globals" config with a `marko` property.
-An additional `taglib` property can be set which supports an `excludeDirs` and `excludePackages` array which will prevent Marko from discovering taglibs in a directory or package respectively.
+An additional `taglib` property can be set which supports `excludeDirs` and `excludePackages` arrays which will prevent Marko from discovering taglibs in a directory or package respectively. You can also specify a `register` array on this object which will cause a taglib to be registered unconditionally for every template.
 
 **jest.config.js**
 
@@ -119,6 +119,7 @@ module.exports = {
     marko: {
       ignoreUnrecognizedTags: true,
       taglib: {
+        register: ["@marko/compat-v4"],
         excludePackages: ["@scope/package-name"],
       },
     },
diff --git a/src/transform/create-transform.ts b/src/transform/create-transform.ts
index 2e5155c..a2fd22f 100644
--- a/src/transform/create-transform.ts
+++ b/src/transform/create-transform.ts
@@ -63,6 +63,17 @@ export default ({ browser }: { browser: boolean }) => {
                 taglib.excludePackage(name);
               }
             }
+
+            const register = taglibConfig.register;
+            if (register) {
+              for (const name of register) {
+                if (typeof name === "string") {
+                  taglib.register(name);
+                } else if (Array.isArray(name) && name.length === 2) {
+                  taglib.register(name[0], name[1]);
+                }
+              }
+            }
           }
         }
       }