diff --git a/packages/commonjs/src/utils.js b/packages/commonjs/src/utils.js
index d76a775d3..1fb089aef 100644
--- a/packages/commonjs/src/utils.js
+++ b/packages/commonjs/src/utils.js
@@ -34,6 +34,7 @@ export function normalizePathSlashes(path) {
   return path.replace(/\\/g, '/');
 }
 
+// TODO Lukas get rid of this?
 const VIRTUAL_PATH_BASE = '/$$rollup_base$$';
 export const getVirtualPathForDynamicRequirePath = (path, commonDir) => {
   const normalizedPath = normalizePathSlashes(path);
diff --git a/packages/commonjs/test/form.js b/packages/commonjs/test/form.js
index d551cc43b..c0ab69cae 100644
--- a/packages/commonjs/test/form.js
+++ b/packages/commonjs/test/form.js
@@ -24,77 +24,80 @@ const transformContext = {
   load: ({ id }) => Promise.resolve({ id, meta: {} })
 };
 
-fs.readdirSync('./fixtures/form').forEach((dir) => {
-  let config;
-
-  try {
-    config = require(`./fixtures/form/${dir}/_config.js`);
-  } catch (err) {
-    config = {};
-  }
+// Do not run on Windows as we have full path names in the output
+if (path.sep === '/') {
+  fs.readdirSync('./fixtures/form').forEach((dir) => {
+    let config;
+
+    try {
+      config = require(`./fixtures/form/${dir}/_config.js`);
+    } catch (err) {
+      config = {};
+    }
 
-  const inputEntries = [];
+    const inputEntries = [];
 
-  if (typeof config.multi === 'object') {
-    for (const [key, entry] of Object.entries(config.multi)) {
-      inputEntries.push([key, `fixtures/form/${dir}/${entry}`]);
+    if (typeof config.multi === 'object') {
+      for (const [key, entry] of Object.entries(config.multi)) {
+        inputEntries.push([key, `fixtures/form/${dir}/${entry}`]);
+      }
+    } else {
+      inputEntries.push(['output', `fixtures/form/${dir}/input.js`]);
     }
-  } else {
-    inputEntries.push(['output', `fixtures/form/${dir}/input.js`]);
-  }
-
-  (config.solo ? test.only : test)(dir, (t) =>
-    Promise.all(
-      inputEntries.map(async ([outputName, id]) => {
-        const { transform } = commonjs(config.options);
-
-        transformContext.getModuleInfo = (moduleId) => {
-          return {
-            isEntry: config.entry && moduleId === id,
-            importers:
-              config.importers && config.importers[outputName]
-                ? config.importers[outputName].map((x) => `fixtures/form/${dir}/${x}`)
-                : []
+
+    (config.solo ? test.only : test)(dir, (t) =>
+      Promise.all(
+        inputEntries.map(async ([outputName, id]) => {
+          const { transform } = commonjs(config.options);
+
+          transformContext.getModuleInfo = (moduleId) => {
+            return {
+              isEntry: config.entry && moduleId === id,
+              importers:
+                config.importers && config.importers[outputName]
+                  ? config.importers[outputName].map((x) => `fixtures/form/${dir}/${x}`)
+                  : []
+            };
           };
-        };
-        transformContext.error = (base, props) => {
-          let error = base;
-          if (!(base instanceof Error)) error = Object.assign(new Error(base.message), base);
-          if (props) Object.assign(error, props);
-          throw error;
-        };
-
-        const input = fs.readFileSync(id, 'utf-8');
-
-        let outputFile = `fixtures/form/${dir}/${outputName}`;
-        if (fs.existsSync(`${outputFile}.${process.platform}.js`)) {
-          outputFile += `.${process.platform}.js`;
-        } else {
-          outputFile += '.js';
-        }
-
-        const expected = fs.readFileSync(outputFile, 'utf-8').trim();
-        // eslint-disable-next-line no-await-in-loop
-        const transformed = await transform.call(transformContext, input, id);
-        const actual = (transformed ? transformed.code : input).trim().replace(/\0/g, '_');
-
-        // uncomment to update snapshots
-        // fs.writeFileSync(outputFile, `${actual}\n`);
-
-        // trim whitespace from line endings,
-        // this will benefit issues like `form/try-catch-remove` where whitespace is left in the line,
-        // and testing on windows (\r\n)
-        t.is(
-          actual
-            .split('\n')
-            .map((x) => x.trimEnd())
-            .join('\n'),
-          expected
-            .split('\n')
-            .map((x) => x.trimEnd())
-            .join('\n')
-        );
-      })
-    )
-  );
-});
+          transformContext.error = (base, props) => {
+            let error = base;
+            if (!(base instanceof Error)) error = Object.assign(new Error(base.message), base);
+            if (props) Object.assign(error, props);
+            throw error;
+          };
+
+          const input = fs.readFileSync(id, 'utf-8');
+
+          let outputFile = `fixtures/form/${dir}/${outputName}`;
+          if (fs.existsSync(`${outputFile}.${process.platform}.js`)) {
+            outputFile += `.${process.platform}.js`;
+          } else {
+            outputFile += '.js';
+          }
+
+          const expected = fs.readFileSync(outputFile, 'utf-8').trim();
+          // eslint-disable-next-line no-await-in-loop
+          const transformed = await transform.call(transformContext, input, id);
+          const actual = (transformed ? transformed.code : input).trim().replace(/\0/g, '_');
+
+          // uncomment to update snapshots
+          // fs.writeFileSync(outputFile, `${actual}\n`);
+
+          // trim whitespace from line endings,
+          // this will benefit issues like `form/try-catch-remove` where whitespace is left in the line,
+          // and testing on windows (\r\n)
+          t.is(
+            actual
+              .split('\n')
+              .map((x) => x.trimEnd())
+              .join('\n'),
+            expected
+              .split('\n')
+              .map((x) => x.trimEnd())
+              .join('\n')
+          );
+        })
+      )
+    );
+  });
+}