diff --git a/index.js b/index.js
index 6c7a989..6900a08 100644
--- a/index.js
+++ b/index.js
@@ -6,7 +6,7 @@ const LineDiff = require('line-diff');
 const bannerMessage =
   '// This file is automatically generated.\n// Please do not change this file!';
 
-const cssModuleExport = 'declare var cssExports: CssExports;\nexport = cssExports;\n';
+const cssModuleExport = 'declare const cssExports: CssExports;\nexport = cssExports;\n';
 
 const getNoDeclarationFileError = ({ filename }) =>
   new Error(
diff --git a/test/emit-declaration/__snapshots__/emit-declaration.test.js.snap b/test/emit-declaration/__snapshots__/emit-declaration.test.js.snap
index e58bc9e..5783de5 100644
--- a/test/emit-declaration/__snapshots__/emit-declaration.test.js.snap
+++ b/test/emit-declaration/__snapshots__/emit-declaration.test.js.snap
@@ -9,7 +9,7 @@ interface CssExports {
   'someClass': string;
   'validClass': string;
 }
-declare var cssExports: CssExports;
+declare const cssExports: CssExports;
 export = cssExports;
 "
 `;
@@ -23,7 +23,7 @@ interface CssExports {
   'someClass': string;
   'validClass': string;
 }
-declare var cssExports: CssExports;
+declare const cssExports: CssExports;
 export = cssExports;
 "
 `;
diff --git a/test/emit-empty-declaration/__snapshots__/emit-empty-declaration.test.js.snap b/test/emit-empty-declaration/__snapshots__/emit-empty-declaration.test.js.snap
index 9ecd79a..3016d3c 100644
--- a/test/emit-empty-declaration/__snapshots__/emit-empty-declaration.test.js.snap
+++ b/test/emit-empty-declaration/__snapshots__/emit-empty-declaration.test.js.snap
@@ -6,7 +6,7 @@ exports[`Can emit valid declaration without classes 1`] = `
 interface CssExports {
 
 }
-declare var cssExports: CssExports;
+declare const cssExports: CssExports;
 export = cssExports;
 "
 `;
diff --git a/test/verify-invalid-declaration/__snapshots__/verify-invalid-declaration.test.js.snap b/test/verify-invalid-declaration/__snapshots__/verify-invalid-declaration.test.js.snap
index 06b3ea9..ddd27e0 100644
--- a/test/verify-invalid-declaration/__snapshots__/verify-invalid-declaration.test.js.snap
+++ b/test/verify-invalid-declaration/__snapshots__/verify-invalid-declaration.test.js.snap
@@ -10,7 +10,7 @@ exports[`Can error on invalid declaration 1`] = `
  -   'classInTypeScriptFile': string;
  +   'classInCssFile': string;
    }
-   declare var cssExports: CssExports;
+   declare const cssExports: CssExports;
    export = cssExports;
    
 
diff --git a/test/verify-invalid-declaration/index.css.d.ts b/test/verify-invalid-declaration/index.css.d.ts
index 6c60747..af6bbc1 100644
--- a/test/verify-invalid-declaration/index.css.d.ts
+++ b/test/verify-invalid-declaration/index.css.d.ts
@@ -4,5 +4,5 @@ interface CssExports {
   'classInBothFiles': string;
   'classInTypeScriptFile': string;
 }
-declare var cssExports: CssExports;
+declare const cssExports: CssExports;
 export = cssExports;
diff --git a/test/verify-valid-declaration/index.css.d.ts b/test/verify-valid-declaration/index.css.d.ts
index 2808c59..9d0e166 100644
--- a/test/verify-valid-declaration/index.css.d.ts
+++ b/test/verify-valid-declaration/index.css.d.ts
@@ -7,5 +7,5 @@ interface CssExports {
   'underscored_classname': string;
   'validClass': string;
 }
-declare var cssExports: CssExports;
+declare const cssExports: CssExports;
 export = cssExports;