diff --git a/lib/file_system.js b/lib/file_system.js
index 2824be82..f09a3a07 100644
--- a/lib/file_system.js
+++ b/lib/file_system.js
@@ -87,18 +87,18 @@ class FileSystem {
     const onlySymlinks = {}
     for (const fullPath in symlinks) {
       if (symlinks[fullPath]) {
-        const relativeToRepoPath = path.relative(this.targetDir, fullPath).split(path.sep).join('/')
+        const relativeToRepoPath = this.normalizePath(path.relative(this.targetDir, fullPath))
         onlySymlinks[relativeToRepoPath] = true
       }
     }
 
     // Remove all symlinks
-    return filePaths.filter(filePath => !onlySymlinks[filePath])
+    return filePaths.filter(filePath => !onlySymlinks[this.normalizePath(filePath)])
   }
 
-  glob (globs, options) {
-    return glob(globs, options)
-      .then(res => res.filter(relativePath => this.shouldInclude(relativePath)))
+  async glob (globs, options) {
+    const fixedGlobs = typeof globs === 'string' ? this.normalizePath(globs) : globs.map(g => this.normalizePath(g))
+    return (await glob(fixedGlobs, options)).map(p => this.normalizePath(p)).filter(p => this.shouldInclude(p))
   }
 
   /**
@@ -112,7 +112,8 @@ class FileSystem {
    * @returns {Promise<Array<string>>} A list of paths relative to this.targetDir
    */
   async findAll (globs, nocase = false) {
-    return this.glob(globs, { cwd: this.targetDir, nocase: !!nocase })
+    const fixedGlobs = typeof globs === 'string' ? this.normalizePath(globs) : globs.map(g => this.normalizePath(g))
+    return this.glob(fixedGlobs, { cwd: this.targetDir, nocase: !!nocase })
   }
 
   async isBinaryFile (relativeFile) {
@@ -130,8 +131,18 @@ class FileSystem {
 
   shouldInclude (filePath) {
     if (this.filterPaths.length === 0) { return true }
-    const resolvedPath = path.relative(this.targetDir, path.resolve(this.targetDir, filePath))
-    return this.filterPaths.some(p => resolvedPath.startsWith(p))
+    const resolvedPath = this.normalizePath(path.relative(this.targetDir, path.resolve(this.targetDir, filePath)))
+    return this.filterPaths
+      .map(p => this.normalizePath(p))
+      .some(p => resolvedPath.startsWith(p))
+  }
+
+  normalizePath (filepath) {
+    if (process.platform === 'win32') {
+      return filepath.split(path.sep).join('/')
+    } else {
+      return filepath
+    }
   }
 
   /**
@@ -142,11 +153,11 @@ class FileSystem {
    */
   async getFileContents (relativeFile) {
     const file = path.resolve(this.targetDir, relativeFile)
-    const exists = await FileSystem.fileExists(file)
-    if (exists && (await fs.promises.stat(file)).isFile()) {
-      return fs.promises.readFile(file, 'utf8')
+    try {
+      return await fs.promises.readFile(file, 'utf8')
+    } catch (e) {
+      return undefined
     }
-    return undefined
   }
 
   /**
@@ -177,7 +188,7 @@ class FileSystem {
     try {
       fd = await fs.promises.open(path.resolve(this.targetDir, file), 'r')
     } catch (e) {
-      fd.close()
+      if (fd) fd.close()
       // File doesn't exist or is a directory
       if (e.message.includes('ENOENT')) {
         return undefined
diff --git a/package-lock.json b/package-lock.json
index 7cf4384e..ad91b36e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "repolinter",
-  "version": "0.8.2",
+  "version": "1.0.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/rules/file-contents.js b/rules/file-contents.js
index 25474e38..ea60316f 100644
--- a/rules/file-contents.js
+++ b/rules/file-contents.js
@@ -31,9 +31,12 @@ async function fileContents (fs, options, not = false) {
   }
 
   const results = await Promise.all(files.map(async file => {
-    let fileContents = await fs.getFileContents(file)
+    const fileContents = await fs.getFileContents(file)
     if (fileContents === undefined) {
-      fileContents = ''
+      return new Result(
+        'Did not find file matching the specified patterns',
+        fileList.map(f => { return { passed: false, pattern: f } }),
+        !options['fail-on-non-existent'])
     }
     const regexp = new RegExp(options.content, options.flags)