diff --git a/index.js b/index.js
index d2cb976..ece5378 100755
--- a/index.js
+++ b/index.js
@@ -18,12 +18,14 @@ var defaults = {
   mediaQuery: false,
   replace: true,
   landscape: false,
-  landscapeUnit: 'vh'
+  landscapeUnit: 'vw',
+  landscapeWidth: 568
 };
 
 module.exports = postcss.plugin('postcss-px-to-viewport', function (options) {
   
   var opts = objectAssign({}, defaults, options);
+
   var pxRegex = getUnitRegexp(opts.unitToConvert);
   var satisfyPropList = createPropListMatcher(opts.propList);
   var landscapeRules = [];
@@ -32,42 +34,63 @@ module.exports = postcss.plugin('postcss-px-to-viewport', function (options) {
     css.walkRules(function (rule) {
       // Add exclude option to ignore some files like 'node_modules'
       var file = rule.source.input.file;
-      
+
       if (opts.exclude && file) {
         if (Object.prototype.toString.call(opts.exclude) === '[object RegExp]') {
-          if (!handleExclude(opts.exclude, file)) return;
+          if (isExclude(opts.exclude, file)) return;
         } else if (Object.prototype.toString.call(opts.exclude) === '[object Array]') {
           for (let i = 0; i < opts.exclude.length; i++) {
-            if (!handleExclude(opts.exclude[i], file)) return;
+            if (isExclude(opts.exclude[i], file)) return;
           }
         } else {
           throw new Error('options.exclude should be RegExp or Array.');
         }
       }
       
-      if (!validateParams(rule.parent.params, opts.mediaQuery)) return;
       if (blacklistedSelector(opts.selectorBlackList, rule.selector)) return;
-      
+
       if (opts.landscape && !rule.parent.params) {
         var landscapeRule = rule.clone().removeAll();
-        landscapeRules.push(landscapeRule);
-        
+
         rule.walkDecls(function(decl) {
           if (decl.value.indexOf(opts.unitToConvert) === -1) return;
           if (!satisfyPropList(decl.prop)) return;
           
-          landscapeRule.append(decl.clone({
-            value: decl.value.replace(pxRegex, createPxReplace(opts, opts.landscapeUnit))
-          }));
+          var landscapeDecl = decl.clone({
+            value: decl.value.replace(pxRegex, createPxReplace(opts, opts.landscapeUnit, opts.landscapeWidth))
+          });
+          
+          if (opts.replace) {
+            landscapeRule.append(landscapeDecl);
+          } else {
+            landscapeRule.append([decl.clone(), landscapeDecl]);
+          }
         });
+        
+        if (landscapeRule.nodes.length > 0) {
+          landscapeRules.push(landscapeRule); 
+        }
       }
+
+      if (!validateParams(rule.parent.params, opts.mediaQuery)) return;
       
       rule.walkDecls(function(decl, i) {
         if (decl.value.indexOf(opts.unitToConvert) === -1) return;
         if (!satisfyPropList(decl.prop)) return;
 
-        var unit = getUnit(decl.prop, opts);
-        var value = decl.value.replace(pxRegex, createPxReplace(opts, unit));
+        var unit;
+        var size;
+        var params = rule.parent.params;
+        
+        if (opts.landscape && params && params.indexOf('landscape') !== -1) {
+          unit = opts.landscapeUnit;
+          size = opts.landscapeWidth;
+        } else {
+          unit = getUnit(decl.prop, opts);
+          size = opts.viewportWidth;
+        }
+        
+        var value = decl.value.replace(pxRegex, createPxReplace(opts, unit, size));
         
         if (declarationExists(decl.parent, decl.prop, value)) return;
         
@@ -82,29 +105,24 @@ module.exports = postcss.plugin('postcss-px-to-viewport', function (options) {
     if (landscapeRules.length > 0) {
       var landscapeRoot = new postcss.atRule({ params: '(orientation: landscape)', name: 'media' });
       
-      landscapeRules.forEach(rule => landscapeRoot.append(rule));
+      landscapeRules.forEach(function(rule) {
+        landscapeRoot.append(rule);
+      });
       css.append(landscapeRoot);
     }
   };
 });
 
-function handleExclude (reg, file) {
-  if (Object.prototype.toString.call(reg) !== '[object RegExp]') {
-    throw new Error('options.exclude should be RegExp.');
-  }
-  return file.match(reg) === null;
-} 
-
 function getUnit(prop, opts) {
   return prop.indexOf('font') === -1 ? opts.viewportUnit : opts.fontViewportUnit;
 }
 
-function createPxReplace(opts, viewportUnit) {
+function createPxReplace(opts, viewportUnit, viewportSize) {
   return function (m, $1) {
     if (!$1) return m;
     var pixels = parseFloat($1);
     if (pixels <= opts.minPixelValue) return m;
-    var parsedVal = toFixed((pixels / opts.viewportWidth * 100), opts.unitPrecision);
+    var parsedVal = toFixed((pixels / viewportSize * 100), opts.unitPrecision);
     return parsedVal === 0 ? '0' : parsedVal + viewportUnit;
   };
 }
@@ -123,6 +141,13 @@ function blacklistedSelector(blacklist, selector) {
   });
 }
 
+function isExclude(reg, file) {
+  if (Object.prototype.toString.call(reg) !== '[object RegExp]') {
+    throw new Error('options.exclude should be RegExp.');
+  }
+  return file.match(reg) !== null;
+}
+
 function declarationExists(decls, prop, value) {
   return decls.some(function (decl) {
       return (decl.prop === prop && decl.value === value);
@@ -130,5 +155,5 @@ function declarationExists(decls, prop, value) {
 }
 
 function validateParams(params, mediaQuery) {
-  return !params || (params && mediaQuery && params.indexOf('landscape') === -1);
+  return !params || (params && mediaQuery);
 }
diff --git a/spec/px-to-viewport.spec.js b/spec/px-to-viewport.spec.js
index d327259..6e5235d 100644
--- a/spec/px-to-viewport.spec.js
+++ b/spec/px-to-viewport.spec.js
@@ -222,12 +222,13 @@ describe('mediaQuery', function () {
     expect(processed).toBe(expected);
   });
   
-  it('should not replace px inside media queries if it has params orientation landscape', function() {
+  it('should replace px inside media queries if it has params orientation landscape and landscape option', function() {
     var options = {
-      mediaQuery: true
+      mediaQuery: true,
+      landscape: true
     };
     var processed = postcss(pxToViewport(options)).process('@media (orientation-landscape) and (min-width: 500px) { .rule { font-size: 16px } }').css;
-    var expected = '@media (orientation-landscape) and (min-width: 500px) { .rule { font-size: 16px } }';
+    var expected = '@media (orientation-landscape) and (min-width: 500px) { .rule { font-size: 2.8169vw } }';
 
     expect(processed).toBe(expected);
   });
@@ -392,7 +393,7 @@ describe('filter-prop-list', function () {
 describe('landscape', function() {
   it('should add landscape atRule', function() {
     var css = '.rule { font-size: 16px; margin: 16px; margin-left: 5px; padding: 5px; padding-right: 16px }';
-    var expected = '.rule { font-size: 5vw; margin: 5vw; margin-left: 1.5625vw; padding: 1.5625vw; padding-right: 5vw }@media (orientation: landscape) {.rule { font-size: 5vh; margin: 5vh; margin-left: 1.5625vh; padding: 1.5625vh; padding-right: 5vh } }';
+    var expected = '.rule { font-size: 5vw; margin: 5vw; margin-left: 1.5625vw; padding: 1.5625vw; padding-right: 5vw }@media (orientation: landscape) {.rule { font-size: 2.8169vw; margin: 2.8169vw; margin-left: 0.88028vw; padding: 0.88028vw; padding-right: 2.8169vw } }';
     var options = {
       landscape: true
     };
@@ -403,10 +404,10 @@ describe('landscape', function() {
 
   it('should add landscape atRule with specified landscapeUnits', function() {
     var css = '.rule { font-size: 16px; margin: 16px; margin-left: 5px; padding: 5px; padding-right: 16px }';
-    var expected = '.rule { font-size: 5vw; margin: 5vw; margin-left: 1.5625vw; padding: 1.5625vw; padding-right: 5vw }@media (orientation: landscape) {.rule { font-size: 5vw; margin: 5vw; margin-left: 1.5625vw; padding: 1.5625vw; padding-right: 5vw } }';
+    var expected = '.rule { font-size: 5vw; margin: 5vw; margin-left: 1.5625vw; padding: 1.5625vw; padding-right: 5vw }@media (orientation: landscape) {.rule { font-size: 2.8169vh; margin: 2.8169vh; margin-left: 0.88028vh; padding: 0.88028vh; padding-right: 2.8169vh } }';
     var options = {
       landscape: true,
-      landscapeUnit: 'vw'
+      landscapeUnit: 'vh'
     };
     var processed = postcss(pxToViewport(options)).process(css).css;
 
@@ -425,13 +426,35 @@ describe('landscape', function() {
     expect(processed).toBe(expected);
   });
   
-  it('should not replace values inside landscape atRule', function() {
+  it('should replace values inside landscape atRule', function() {
     var options = {
       replace: false,
       landscape: true
     };
     var processed = postcss(pxToViewport(options)).process(basicCSS).css;
-    var expected = '.rule { font-size: 15px; font-size: 4.6875vw }@media (orientation: landscape) {.rule { font-size: 4.6875vh } }';
+    var expected = '.rule { font-size: 15px; font-size: 4.6875vw }@media (orientation: landscape) {.rule { font-size: 15px; font-size: 2.64085vw } }';
+
+    expect(processed).toBe(expected);
+  });
+  
+  it('should add landscape atRule with specified landscapeWidth', function() {
+    var options = {
+      landscape: true,
+      landscapeWidth: 768
+    };
+    var processed = postcss(pxToViewport(options)).process(basicCSS).css;
+    var expected = '.rule { font-size: 4.6875vw }@media (orientation: landscape) {.rule { font-size: 1.95313vw } }';
+
+    expect(processed).toBe(expected);
+  });
+  
+  it('should not add landscape atRule if it has no nodes', function() {
+    var css = '.rule { font-size: 15vw }';
+    var options = {
+      landscape: true
+    };
+    var processed = postcss(pxToViewport(options)).process(css).css;
+    var expected = '.rule { font-size: 15vw }';
 
     expect(processed).toBe(expected);
   })