diff --git a/packages/ojs/external-observablehq-parser/package.json b/packages/ojs/external-observablehq-parser/package.json
index 5f816514..f421bec6 100644
--- a/packages/ojs/external-observablehq-parser/package.json
+++ b/packages/ojs/external-observablehq-parser/package.json
@@ -37,7 +37,7 @@
     "external-observablehq-parser": "./src/index.js"
   },
   "dependencies": {
-    "acorn": "8",
+    "acorn": "8.16.0",
     "acorn-walk": "8.3.5"
   },
   "devDependencies": {
diff --git a/packages/ojs/external-observablehq-parser/yarn.lock b/packages/ojs/external-observablehq-parser/yarn.lock
index e5b04805..269489ea 100644
--- a/packages/ojs/external-observablehq-parser/yarn.lock
+++ b/packages/ojs/external-observablehq-parser/yarn.lock
@@ -74,7 +74,12 @@ acorn-walk@8.3.5:
   dependencies:
     acorn "^8.11.0"
 
-acorn@8, acorn@^8.6.0:
+acorn@8.16.0:
+  version "8.16.0"
+  resolved "https://registry.yarnpkg.com/acorn/-/acorn-8.16.0.tgz#4ce79c89be40afe7afe8f3adb902a1f1ce9ac08a"
+  integrity sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw==
+
+acorn@^8.6.0:
   version "8.6.0"
   resolved "https://registry.npmjs.org/acorn/-/acorn-8.6.0.tgz"
   integrity sha512-U1riIR+lBSNi3IbxtaHOIKdH8sLFv3NYfNv8sg7ZsNhcfl4HF2++BfqqrNAxoCLQW1iiylOj76ecnaUxz+z9yw==