diff --git a/packages/docs/package.json b/packages/docs/package.json
index c9cd9b2199..a525813dcd 100644
--- a/packages/docs/package.json
+++ b/packages/docs/package.json
@@ -45,7 +45,7 @@
     "classnames": "2.2.6",
     "core-js": "3.6.5",
     "ethers": "5.0.32",
-    "mobx": "6.0.4",
+    "mobx": "5.15.6",
     "react": "16.13.1",
     "react-dom": "16.13.1",
     "redoc": "2.0.0-rc.40",
diff --git a/yarn.lock b/yarn.lock
index 75919488a3..8bed9b2add 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -14331,10 +14331,10 @@ mobx-react@^6.2.2:
   dependencies:
     mobx-react-lite ">=2.2.0"
 
-mobx@6.0.4:
-  version "6.0.4"
-  resolved "https://registry.yarnpkg.com/mobx/-/mobx-6.0.4.tgz#8fc3e3629a3346f8afddf5bd954411974744dad1"
-  integrity sha512-wT2QJT9tW19VSHo9x7RPKU3z/I2Ps6wUS8Kb1OO+kzmg7UY3n4AkcaYG6jq95Lp1R9ohjC/NGYuT2PtuvBjhFg==
+mobx@5.15.6:
+  version "5.15.6"
+  resolved "https://registry.yarnpkg.com/mobx/-/mobx-5.15.6.tgz#24750af56f87bcf9c3cf82ece4c79eb91bb71968"
+  integrity sha512-U5nnx3UNdRkUjntpwzO060VWifGVx/JZeu/aMw4y28dTjDNjoY3vNKs6tFNm7z1qIfcPInsd9L9HIm8H0zTDqg==
 
 mocha@8.1.2:
   version "8.1.2"