diff --git a/src/index.js b/src/index.js
index dae72bd..f1c2758 100644
--- a/src/index.js
+++ b/src/index.js
@@ -4,13 +4,13 @@ const METHOD = 'map-get';
 
 const valResolve = value => {
   const map = value.substring(
-      value.indexOf('((') + 2,
-      value.indexOf('),')
-    )
+    value.indexOf('((') + 2,
+    value.indexOf('),')
+  )
     .split(',')
     .reduce((map, string) => {
       const [key, value] = string.split(':');
-      return Object.assign(map, {[key]: value})
+      return Object.assign(map, {[key]: value});
     }, {});
 
   const key = value.substring(
@@ -19,18 +19,25 @@ const valResolve = value => {
   );
 
   return map[key];
-}
+};
 
 const normalize = value => value.replace(/(\s|!default)/g, '');
 
 export default postcss.plugin('postcss-map-get', () => {
-    return nodes => {
-        nodes.walkDecls(decl => {
-          let {value} = decl;
-
-          if (value.startsWith(METHOD)) {
-            decl.value = valResolve(normalize(decl.value));
-          }
-        });
-    };
+  return nodes => {
+    nodes.walkDecls(decl => {
+      let {value} = decl;
+
+      if (value.startsWith(METHOD)) {
+        decl.value = valResolve(normalize(decl.value));
+      }
+    });
+
+    nodes.walkAtRules(rules => {
+      const {params} = rules;
+      const start = params.indexOf(METHOD);
+      const end = params.lastIndexOf('))');
+      rules.params = `${params.substr(0, start)}${valResolve(normalize(params.substring(start, end)))}${params.substr(end + 1)}`;
+    });
+  };
 });
diff --git a/test/test.js b/test/test.js
index 0809653..ca8af6c 100644
--- a/test/test.js
+++ b/test/test.js
@@ -3,18 +3,24 @@ import test from 'ava';
 import plugin from '../src';
 
 const processing = (input, opts) => {
-    return postcss([plugin(opts)]).process(input).css;
+  return postcss([plugin(opts)]).process(input).css;
 };
 
 test('it should return body color for background', t => {
-    const expected = 'body{background: #fff;}';
-    const value = 'body{background: map-get((body: #fff,main-red: #c53831,link-blue: #0592fb) !default, body);}';
-    t.is(processing(value), expected);
+  const expected = 'body{background: #fff;}';
+  const value = 'body{background: map-get((body: #fff,main-red: #c53831,link-blue: #0592fb) !default, body);}';
+  t.is(processing(value), expected);
 });
 
 test('it should return body color and min-width width fro decl', t => {
-    const expected = 'body{background: #fff;min-width: 1280px;}';
-    const value = 'body{background: map-get((body: #fff,main-red: #c53831,link-blue: #0592fb) !default, body);min-width: map-get((xxs: 0,xs: 576px,sm: 768px,md: 992px,lg: 1280px,xl: 1360px,xxl: 1600px) !default, lg);}';
-    t.is(processing(value), expected);
+  const expected = 'body{background: #fff;min-width: 1280px;}';
+  const value = 'body{background: map-get((body: #fff,main-red: #c53831,link-blue: #0592fb) !default, body);min-width: map-get((xxs: 0,xs: 576px,sm: 768px,md: 992px,lg: 1280px,xl: 1360px,xxl: 1600px) !default, lg);}';
+  t.is(processing(value), expected);
+});
+
+test('it should retunr width for at rule @media', t => {
+  const expected = '@media (min-width: 1280px) {body {overflow-x: hidden}}';
+  const value = '@media (min-width: map-get((xxs: 0,xs: 576px,sm: 768px,md: 992px,lg: 1280px,xl: 1360px,xxl: 1600px) !default, lg))) {body {overflow-x: hidden}}';
+  t.is(processing(value), expected);
 });