diff --git a/src/index.js b/src/index.js
index a0771805..cb23147e 100644
--- a/src/index.js
+++ b/src/index.js
@@ -162,7 +162,9 @@ export default async function loader(content, sourceMap, meta) {
           }
 
           if (pkg) {
-            if (!pkg.dependencies.postcss && !pkg.devDependencies.postcss) {
+            const { dependencies = {}, devDependencies = {} } = pkg;
+
+            if (!dependencies.postcss && !devDependencies.postcss) {
               this.emitWarning(
                 new Error(
                   "Add postcss as project dependency. postcss is not a peer dependency for postcss-loader. " +
diff --git a/test/fixtures/package-json-files/no-postcss/package.json b/test/fixtures/package-json-files/no-postcss/package.json
index 255dac01..0967ef42 100644
--- a/test/fixtures/package-json-files/no-postcss/package.json
+++ b/test/fixtures/package-json-files/no-postcss/package.json
@@ -1,4 +1 @@
-{
-  "dependencies": {},
-  "devDependencies": {}
-}
\ No newline at end of file
+{}
diff --git a/test/fixtures/package-json-files/postcss-v8-in-dependencies/package.json b/test/fixtures/package-json-files/postcss-v8-in-dependencies/package.json
index 7e20ba4d..2003d907 100644
--- a/test/fixtures/package-json-files/postcss-v8-in-dependencies/package.json
+++ b/test/fixtures/package-json-files/postcss-v8-in-dependencies/package.json
@@ -1,6 +1,5 @@
 {
   "dependencies": {
     "postcss": "^8.0.0"
-  },
-  "devDependencies": {}
-}
\ No newline at end of file
+  }
+}
diff --git a/test/fixtures/package-json-files/postcss-v8-in-devDependencies/package.json b/test/fixtures/package-json-files/postcss-v8-in-devDependencies/package.json
index 0712e31c..b750286e 100644
--- a/test/fixtures/package-json-files/postcss-v8-in-devDependencies/package.json
+++ b/test/fixtures/package-json-files/postcss-v8-in-devDependencies/package.json
@@ -1,6 +1,5 @@
 {
-  "dependencies": {},
   "devDependencies": {
     "postcss": "^8.0.0"
   }
-}
\ No newline at end of file
+}