diff --git a/package.json b/package.json
index 6f97f752012..cda31d898de 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,7 @@
     "@webassemblyjs/helper-module-context": "1.9.0",
     "@webassemblyjs/wasm-edit": "1.9.0",
     "@webassemblyjs/wasm-parser": "1.9.0",
-    "acorn": "^6.2.1",
+    "acorn": "^6.4.1",
     "ajv": "^6.10.2",
     "ajv-keywords": "^3.4.1",
     "chrome-trace-event": "^1.0.2",
diff --git a/yarn.lock b/yarn.lock
index b0004185182..f1465ff4742 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -684,14 +684,14 @@ acorn@^4.0.4, acorn@~4.0.2:
   integrity sha1-EFSVrlNh1pe9GVyCUZLhrX8lN4c=
 
 acorn@^5.5.3:
-  version "5.7.3"
-  resolved "https://registry.yarnpkg.com/acorn/-/acorn-5.7.3.tgz#67aa231bf8812974b85235a96771eb6bd07ea279"
-  integrity sha512-T/zvzYRfbVojPWahDsE5evJdHb3oJoQfFbsrKM7w5Zcs++Tr257tia3BmMP8XYVjp1S9RZXQMh7gao96BlqZOw==
-
-acorn@^6.0.1, acorn@^6.0.7, acorn@^6.2.1:
-  version "6.4.0"
-  resolved "https://registry.yarnpkg.com/acorn/-/acorn-6.4.0.tgz#b659d2ffbafa24baf5db1cdbb2c94a983ecd2784"
-  integrity sha512-gac8OEcQ2Li1dxIEWGZzsp2BitJxwkwcOm0zHAJLcPJaVvm58FRnk6RkuLRpU1EujipU2ZFODv2P9DLMfnV8mw==
+  version "5.7.4"
+  resolved "https://registry.yarnpkg.com/acorn/-/acorn-5.7.4.tgz#3e8d8a9947d0599a1796d10225d7432f4a4acf5e"
+  integrity sha512-1D++VG7BhrtvQpNbBzovKNc1FLGGEE/oGe7b9xJm/RFHMBeUaUGpluV9RLjZa47YFdPcDAenEYuq9pQPcMdLJg==
+
+acorn@^6.0.1, acorn@^6.0.7, acorn@^6.4.1:
+  version "6.4.1"
+  resolved "https://registry.yarnpkg.com/acorn/-/acorn-6.4.1.tgz#531e58ba3f51b9dacb9a6646ca4debf5b14ca474"
+  integrity sha512-ZVA9k326Nwrj3Cj9jlh3wGFutC2ZornPNARZwsNYqQYgN0EsV2d53w5RN/co65Ohn4sUAUtb1rSUAOD6XN9idA==
 
 ajv-errors@^1.0.0:
   version "1.0.1"