diff --git a/src/index.js b/src/index.js
index b8bcbed..f4963e0 100644
--- a/src/index.js
+++ b/src/index.js
@@ -114,6 +114,7 @@ export default ({
           }
           replaceJsxExpressionContainer(
             t,
+            path,
             styleNameAttribute,
             filenameMap[filename].importedHelperIndentifier,
             filenameMap[filename].styleModuleImportMapIdentifier
diff --git a/src/replaceJsxExpressionContainer.js b/src/replaceJsxExpressionContainer.js
index 1eb0b45..3faf4e6 100644
--- a/src/replaceJsxExpressionContainer.js
+++ b/src/replaceJsxExpressionContainer.js
@@ -5,16 +5,33 @@ import BabelTypes, {
   Identifier
 } from 'babel-types';
 
-export default (t: BabelTypes, styleNameAttribute: JSXAttribute, importedHelperIndentifier: Identifier, styleModuleImportMapIdentifier: Identifier): void => {
+export default (t: BabelTypes, path: Object, styleNameAttribute: JSXAttribute, importedHelperIndentifier: Identifier, styleModuleImportMapIdentifier: Identifier): void => {
   const expressionContainerValue = styleNameAttribute.value;
+  const classNameAttribute = path.node.openingElement.attributes
+    .find((attribute) => {
+      return typeof attribute.name !== 'undefined' && attribute.name.name === 'className';
+    });
+  const classNameAttributeValue = classNameAttribute ? classNameAttribute.value.value : '';
+
+  if (classNameAttribute) {
+    path.node.openingElement.attributes.splice(path.node.openingElement.attributes.indexOf(classNameAttribute), 1);
+  }
+
+  const styleNameExpression = t.callExpression(
+    importedHelperIndentifier,
+    [
+      expressionContainerValue.expression,
+      styleModuleImportMapIdentifier
+    ]
+  );
 
   styleNameAttribute.value = t.jSXExpressionContainer(
-    t.callExpression(
-      importedHelperIndentifier,
-      [
-        expressionContainerValue.expression,
-        styleModuleImportMapIdentifier
-      ]
-    )
+    classNameAttribute ?
+      t.binaryExpression(
+        '+',
+        t.stringLiteral(classNameAttributeValue + ' '),
+        styleNameExpression
+      ) : styleNameExpression
   );
+  styleNameAttribute.name.name = 'className';
 };
diff --git a/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName bis/actual.js b/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName (with already existing className)/actual.js
similarity index 72%
rename from test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName bis/actual.js
rename to test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName (with already existing className)/actual.js
index f284d12..cb49c7a 100644
--- a/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName bis/actual.js	
+++ b/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName (with already existing className)/actual.js	
@@ -5,4 +5,4 @@ const styleNameBar = 'bar.a-b';
 const styleNameFoo = 'a-b';
 
 <div styleName={styleNameBar}></div>;
-<div styleName={styleNameFoo}></div>;
+<div className='global' styleName={styleNameFoo}></div>;
diff --git a/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName bis/bar.css b/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName (with already existing className)/bar.css
similarity index 100%
rename from test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName bis/bar.css
rename to test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName (with already existing className)/bar.css
diff --git a/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName bis/expected.js b/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName (with already existing className)/expected.js
similarity index 68%
rename from test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName bis/expected.js
rename to test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName (with already existing className)/expected.js
index 41d4f3e..e9f288f 100644
--- a/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName bis/expected.js	
+++ b/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName (with already existing className)/expected.js	
@@ -13,5 +13,5 @@ const _styleModuleImportMap = {
 const styleNameBar = 'bar.a-b';
 const styleNameFoo = 'a-b';
 
-<div styleName={_getClassName(styleNameBar, _styleModuleImportMap)}></div>;
-<div styleName={_getClassName(styleNameFoo, _styleModuleImportMap)}></div>;
+<div className={_getClassName(styleNameBar, _styleModuleImportMap)}></div>;
+<div className={'global ' + _getClassName(styleNameFoo, _styleModuleImportMap)}></div>;
diff --git a/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName bis/foo.css b/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName (with already existing className)/foo.css
similarity index 100%
rename from test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName bis/foo.css
rename to test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName (with already existing className)/foo.css
diff --git a/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName bis/options.json b/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName (with already existing className)/options.json
similarity index 100%
rename from test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName bis/options.json
rename to test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName (with already existing className)/options.json
diff --git a/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName/expected.js b/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName/expected.js
index 41d4f3e..336e388 100644
--- a/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName/expected.js	
+++ b/test/fixtures/react-css-modules/uses getClassName to resolve non-literal styleName/expected.js	
@@ -13,5 +13,5 @@ const _styleModuleImportMap = {
 const styleNameBar = 'bar.a-b';
 const styleNameFoo = 'a-b';
 
-<div styleName={_getClassName(styleNameBar, _styleModuleImportMap)}></div>;
-<div styleName={_getClassName(styleNameFoo, _styleModuleImportMap)}></div>;
+<div className={_getClassName(styleNameBar, _styleModuleImportMap)}></div>;
+<div className={_getClassName(styleNameFoo, _styleModuleImportMap)}></div>;