diff --git a/package.json b/package.json
index 08c757f..739d273 100644
--- a/package.json
+++ b/package.json
@@ -3,7 +3,7 @@
     "babel-core": "^6.25.0",
     "babel-preset-es2015": "^6.24.1",
     "del": "^3.0.0",
-    "ecstatic": "^2.2.1",
+    "ecstatic": "^4.1.4",
     "express": "^4.16.2",
     "gmail-send": "^1.2.11",
     "gulp": "^3.9.1",
diff --git a/yarn.lock b/yarn.lock
index 169fd09..f4a627a 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -720,6 +720,10 @@ character-parser@^2.1.1:
   dependencies:
     is-regex "^1.0.3"
 
+charset@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/charset/-/charset-1.0.1.tgz#8d59546c355be61049a8fa9164747793319852bd"
+
 cheerio@^0.22.0:
   version "0.22.0"
   resolved "https://registry.yarnpkg.com/cheerio/-/cheerio-0.22.0.tgz#a9baa860a3f9b595a6b81b1a86873121ed3a269e"
@@ -1070,14 +1074,16 @@ ecc-jsbn@~0.1.1:
   dependencies:
     jsbn "~0.1.0"
 
-ecstatic@^2.2.1:
-  version "2.2.1"
-  resolved "https://registry.yarnpkg.com/ecstatic/-/ecstatic-2.2.1.tgz#b5087fad439dd9dd49d31e18131454817fe87769"
+ecstatic@^4.1.4:
+  version "4.1.4"
+  resolved "https://registry.yarnpkg.com/ecstatic/-/ecstatic-4.1.4.tgz#86bf340dabe56c4d0c93d406ac36c040f68e1d79"
   dependencies:
+    charset "^1.0.1"
     he "^1.1.1"
-    mime "^1.2.11"
+    mime "^2.4.1"
     minimist "^1.1.0"
-    url-join "^2.0.2"
+    on-finished "^2.3.0"
+    url-join "^4.0.0"
 
 editorconfig@^0.13.2:
   version "0.13.2"
@@ -2494,9 +2500,9 @@ mime@1.4.1:
   version "1.4.1"
   resolved "https://registry.yarnpkg.com/mime/-/mime-1.4.1.tgz#121f9ebc49e3766f311a76e1fa1c8003c4b03aa6"
 
-mime@^1.2.11:
-  version "1.3.6"
-  resolved "https://registry.yarnpkg.com/mime/-/mime-1.3.6.tgz#591d84d3653a6b0b4a3b9df8de5aa8108e72e5e0"
+mime@^2.4.1:
+  version "2.4.6"
+  resolved "https://registry.yarnpkg.com/mime/-/mime-2.4.6.tgz#e5b407c90db442f2beb5b162373d07b69affa4d1"
 
 mimer@^0.2.1:
   version "0.2.1"
@@ -2969,7 +2975,7 @@ object.pick@^1.2.0:
   dependencies:
     isobject "^2.1.0"
 
-on-finished@~2.3.0:
+on-finished@^2.3.0, on-finished@~2.3.0:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/on-finished/-/on-finished-2.3.0.tgz#20f1336481b083cd75337992a16971aa2d906947"
   dependencies:
@@ -3907,9 +3913,9 @@ upper-case@^1.1.1:
   version "1.1.3"
   resolved "https://registry.yarnpkg.com/upper-case/-/upper-case-1.1.3.tgz#f6b4501c2ec4cdd26ba78be7222961de77621598"
 
-url-join@^2.0.2:
-  version "2.0.2"
-  resolved "https://registry.yarnpkg.com/url-join/-/url-join-2.0.2.tgz#c072756967ad24b8b59e5741551caac78f50b8b7"
+url-join@^4.0.0:
+  version "4.0.1"
+  resolved "https://registry.yarnpkg.com/url-join/-/url-join-4.0.1.tgz#b642e21a2646808ffa178c4c5fda39844e12cde7"
 
 user-home@^1.1.1:
   version "1.1.1"