diff --git a/package-lock.json b/package-lock.json
index 1cd18062..16e5b3aa 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2217,9 +2217,9 @@
       "dev": true
     },
     "chokidar": {
-      "version": "2.1.1",
-      "resolved": "https://registry.npmjs.org/chokidar/-/chokidar-2.1.1.tgz",
-      "integrity": "sha512-gfw3p2oQV2wEt+8VuMlNsPjCxDxvvgnm/kz+uATu805mWVF8IJN7uz9DN7iBz+RMJISmiVbCOBFs9qBGMjtPfQ==",
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/chokidar/-/chokidar-2.1.2.tgz",
+      "integrity": "sha512-IwXUx0FXc5ibYmPC2XeEj5mpXoV66sR+t3jqu2NS2GYwCktt3KF1/Qqjws/NkegajBA4RbZ5+DDwlOiJsxDHEg==",
       "dev": true,
       "requires": {
         "anymatch": "^2.0.0",
@@ -3788,9 +3788,9 @@
       }
     },
     "eslint": {
-      "version": "5.14.0",
-      "resolved": "https://registry.npmjs.org/eslint/-/eslint-5.14.0.tgz",
-      "integrity": "sha512-jrOhiYyENRrRnWlMYANlGZTqb89r2FuRT+615AabBoajhNjeh9ywDNlh2LU9vTqf0WYN+L3xdXuIi7xuj/tK9w==",
+      "version": "5.14.1",
+      "resolved": "https://registry.npmjs.org/eslint/-/eslint-5.14.1.tgz",
+      "integrity": "sha512-CyUMbmsjxedx8B0mr79mNOqetvkbij/zrXnFeK2zc3pGRn3/tibjiNAv/3UxFEyfMDjh+ZqTrJrEGBFiGfD5Og==",
       "dev": true,
       "requires": {
         "@babel/code-frame": "^7.0.0",
@@ -4637,7 +4637,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -5052,7 +5053,8 @@
         "safe-buffer": {
           "version": "5.1.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -5108,6 +5110,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -5151,12 +5154,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },
@@ -8117,8 +8122,7 @@
     "normalize-path": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/normalize-path/-/normalize-path-3.0.0.tgz",
-      "integrity": "sha512-6eZs5Ls3WtCisHWp9S2GUy8dqkpGi4BVSz3GaqiE6ezub0512ESztXUwUB6C6IKbQkY2Pnb/mD4WYojCRwcwLA==",
-      "dev": true
+      "integrity": "sha512-6eZs5Ls3WtCisHWp9S2GUy8dqkpGi4BVSz3GaqiE6ezub0512ESztXUwUB6C6IKbQkY2Pnb/mD4WYojCRwcwLA=="
     },
     "npm-path": {
       "version": "2.0.4",
@@ -9061,9 +9065,9 @@
       }
     },
     "regexp-tree": {
-      "version": "0.1.4",
-      "resolved": "https://registry.npmjs.org/regexp-tree/-/regexp-tree-0.1.4.tgz",
-      "integrity": "sha512-DohP6WXzgrc7gFs9GsTQgigUfMXZqXkPk+20qkMF6YCy0Qk0FsHL1/KtxTycGR/62DHRtJ1MHQF2g8YzywP4kA==",
+      "version": "0.1.5",
+      "resolved": "https://registry.npmjs.org/regexp-tree/-/regexp-tree-0.1.5.tgz",
+      "integrity": "sha512-nUmxvfJyAODw+0B13hj8CFVAxhe7fDEAgJgaotBu3nnR+IgGgZq59YedJP5VYTlkEfqjuK6TuRpnymKdatLZfQ==",
       "dev": true
     },
     "regexpp": {
diff --git a/package.json b/package.json
index 543d986f..5e6d4a79 100644
--- a/package.json
+++ b/package.json
@@ -47,7 +47,8 @@
     "is-glob": "^4.0.0",
     "loader-utils": "^1.1.0",
     "minimatch": "^3.0.4",
-    "p-limit": "^2.1.0"
+    "p-limit": "^2.1.0",
+    "normalize-path": "^3.0.0"
   },
   "devDependencies": {
     "@babel/cli": "^7.1.5",
diff --git a/src/preProcessPattern.js b/src/preProcessPattern.js
index 19a9f42f..e1c9c359 100644
--- a/src/preProcessPattern.js
+++ b/src/preProcessPattern.js
@@ -1,8 +1,9 @@
 import path from 'path';
 
 import isGlob from 'is-glob';
+import normalizePath from 'normalize-path';
 
-import escape from './utils/escape';
+import normalize from './utils/normalize';
 import isObject from './utils/isObject';
 import { stat } from './utils/promisify';
 
@@ -41,6 +42,7 @@ export default function preProcessPattern(globalRef, pattern) {
     pattern.context = path.join(context, pattern.context);
   }
 
+  pattern.context = normalizePath(pattern.context);
   pattern.ignore = globalRef.ignore.concat(pattern.ignore || []);
 
   info(`processing from: '${pattern.from}' to: '${pattern.to}'`);
@@ -68,9 +70,11 @@ export default function preProcessPattern(globalRef, pattern) {
     const globOptions = Object.assign({}, pattern.from);
     delete globOptions.glob;
 
-    pattern.glob = escape(pattern.context, pattern.from.glob);
+    pattern.glob = normalize(pattern.context, pattern.from.glob);
     pattern.globOptions = globOptions;
-    pattern.absoluteFrom = path.resolve(pattern.context, pattern.from.glob);
+    pattern.absoluteFrom = normalizePath(
+      path.resolve(pattern.context, pattern.from.glob)
+    );
 
     return Promise.resolve(pattern);
   }
@@ -81,6 +85,9 @@ export default function preProcessPattern(globalRef, pattern) {
     pattern.absoluteFrom = path.resolve(pattern.context, pattern.from);
   }
 
+  // Normalize path when path separators are mixed (like `C:\\directory/nested-directory/`)
+  pattern.absoluteFrom = normalizePath(pattern.absoluteFrom);
+
   debug(
     `determined '${pattern.from}' to be read from '${pattern.absoluteFrom}'`
   );
@@ -89,7 +96,7 @@ export default function preProcessPattern(globalRef, pattern) {
     // If from doesn't appear to be a glob, then log a warning
     if (isGlob(pattern.from) || pattern.from.indexOf('*') !== -1) {
       pattern.fromType = 'glob';
-      pattern.glob = escape(pattern.context, pattern.from);
+      pattern.glob = normalize(pattern.context, pattern.from);
 
       // We need to add context directory as dependencies to avoid problems when new files added in directories
       // when we already in watch mode and this directories are not in context dependencies
@@ -130,7 +137,7 @@ export default function preProcessPattern(globalRef, pattern) {
 
         pattern.fromType = 'dir';
         pattern.context = pattern.absoluteFrom;
-        pattern.glob = escape(pattern.absoluteFrom, '**/*');
+        pattern.glob = normalize(pattern.absoluteFrom, '**/*');
         pattern.absoluteFrom = path.join(pattern.absoluteFrom, '**/*');
         pattern.globOptions = {
           dot: true,
@@ -140,7 +147,7 @@ export default function preProcessPattern(globalRef, pattern) {
 
         pattern.fromType = 'file';
         pattern.context = path.dirname(pattern.absoluteFrom);
-        pattern.glob = escape(pattern.absoluteFrom);
+        pattern.glob = normalize(pattern.absoluteFrom);
         pattern.globOptions = {
           dot: true,
         };
diff --git a/src/processPattern.js b/src/processPattern.js
index 3714a2be..d3446434 100644
--- a/src/processPattern.js
+++ b/src/processPattern.js
@@ -3,6 +3,7 @@ import path from 'path';
 import globby from 'globby';
 import pLimit from 'p-limit';
 import minimatch from 'minimatch';
+import normalizePath from 'normalize-path';
 
 import isObject from './utils/isObject';
 
@@ -41,6 +42,9 @@ export default function processPattern(globalRef, pattern) {
             file.relativeFrom = path.basename(file.relativeFrom);
           }
 
+          // Ensure forward slashes
+          file.relativeFrom = normalizePath(file.relativeFrom);
+
           debug(`found ${from}`);
 
           // Check the ignore list
@@ -106,8 +110,8 @@ export default function processPattern(globalRef, pattern) {
             file.webpackTo = path.relative(output, file.webpackTo);
           }
 
-          // ensure forward slashes
-          file.webpackTo = file.webpackTo.replace(/\\/g, '/');
+          // Ensure forward slashes
+          file.webpackTo = normalizePath(file.webpackTo);
 
           info(`determined that '${from}' should write to '${file.webpackTo}'`);
 
diff --git a/src/utils/escape.js b/src/utils/normalize.js
similarity index 77%
rename from src/utils/escape.js
rename to src/utils/normalize.js
index f5c239df..a2572779 100644
--- a/src/utils/escape.js
+++ b/src/utils/normalize.js
@@ -1,6 +1,8 @@
 import path from 'path';
 
-export default function escape(context, from) {
+import normalizePath from 'normalize-path';
+
+function escape(context, from) {
   if (from && path.isAbsolute(from)) {
     return from;
   }
@@ -24,3 +26,7 @@ export default function escape(context, from) {
 
   return `${absoluteContext}/${from}`;
 }
+
+export default function normalize(context, from) {
+  return normalizePath(escape(context, from));
+}
diff --git a/test/CopyPlugin.test.js b/test/CopyPlugin.test.js
index 8794d2ec..dae176a0 100644
--- a/test/CopyPlugin.test.js
+++ b/test/CopyPlugin.test.js
@@ -10,6 +10,7 @@ import findCacheDir from 'find-cache-dir';
 import cacache from 'cacache';
 import isGzip from 'is-gzip';
 import mkdirp from 'mkdirp';
+import normalizePath from 'normalize-path';
 
 import CopyPlugin from '../src/index';
 
@@ -327,6 +328,7 @@ describe('apply function', () => {
       runEmit({
         expectedAssetKeys: [
           'directory/directoryfile.txt',
+          'directory/nested/deep-nested/deepnested.txt',
           'directory/nested/nestedfile.txt',
           'file.txt',
           'noextension',
@@ -380,6 +382,7 @@ describe('apply function', () => {
           'file.txt',
           'file.txt.gz',
           'directory/directoryfile.txt',
+          'directory/nested/deep-nested/deepnested.txt',
           'directory/nested/nestedfile.txt',
           '[special?directory]/directoryfile.txt',
           '[special?directory]/(special-*file).txt',
@@ -404,6 +407,7 @@ describe('apply function', () => {
           'nested/file.txt',
           'nested/file.txt.gz',
           'nested/directory/directoryfile.txt',
+          'nested/directory/nested/deep-nested/deepnested.txt',
           'nested/directory/nested/nestedfile.txt',
           'nested/[special?directory]/directoryfile.txt',
           'nested/[special?directory]/(special-*file).txt',
@@ -426,6 +430,7 @@ describe('apply function', () => {
         expectedAssetKeys: [
           '/some/path/(special-*file).txt.tst',
           '/some/path/binextension.bin.tst',
+          '/some/path/deepnested.txt.tst',
           '/some/path/file.txt.tst',
           '/some/path/file.txt.gz.tst',
           '/some/path/directoryfile.txt.tst',
@@ -459,6 +464,7 @@ describe('apply function', () => {
           'transformed/file-22af64.txt',
           'transformed/file.txt-5b311c.gz',
           'transformed/directory/directoryfile-22af64.txt',
+          'transformed/directory/nested/deep-nested/deepnested-d41d8c.txt',
           'transformed/directory/nested/nestedfile-d41d8c.txt',
           'transformed/noextension-d41d8c',
         ],
@@ -482,6 +488,7 @@ describe('apply function', () => {
       runEmit({
         expectedAssetKeys: [
           'nested/directoryfile.txt',
+          'nested/nested/deep-nested/deepnested.txt',
           'nested/nested/nestedfile.txt',
         ],
         patterns: [
@@ -535,6 +542,7 @@ describe('apply function', () => {
     it('can use a glob to flatten multiple files in a relative context to a non-root directory', (done) => {
       runEmit({
         expectedAssetKeys: [
+          'nested/deepnested.txt',
           'nested/directoryfile.txt',
           'nested/nestedfile.txt',
         ],
@@ -555,6 +563,7 @@ describe('apply function', () => {
       runEmit({
         expectedAssetKeys: [
           'nested/directoryfile.txt',
+          'nested/nested/deep-nested/deepnested.txt',
           'nested/nested/nestedfile.txt',
         ],
         patterns: [
@@ -588,6 +597,7 @@ describe('apply function', () => {
           '[!]/hello.txt',
           'file.txt',
           'directory/directoryfile.txt',
+          'directory/nested/deep-nested/deepnested.txt',
           'directory/nested/nestedfile.txt',
           '[special?directory]/directoryfile.txt',
           '[special?directory]/(special-*file).txt',
@@ -611,6 +621,7 @@ describe('apply function', () => {
           'nested/file-22af64.txt',
           'nested/file.txt-5b311c.gz',
           'nested/directory/directoryfile-22af64.txt',
+          'nested/directory/nested/deep-nested/deepnested-d41d8c.txt',
           'nested/directory/nested/nestedfile-d41d8c.txt',
           'nested/[special?directory]/(special-*file)-0bd650.txt',
           'nested/[special?directory]/directoryfile-22af64.txt',
@@ -657,9 +668,11 @@ describe('apply function', () => {
         ],
       })
         .then((compilation) => {
-          expect(Array.from(compilation.contextDependencies).sort()).toEqual(
-            [HELPER_DIR].sort()
-          );
+          expect(
+            Array.from(compilation.contextDependencies)
+              .map((contextDependency) => normalizePath(contextDependency))
+              .sort()
+          ).toEqual([normalizePath(HELPER_DIR)].sort());
         })
         .then(done)
         .catch(done);
@@ -767,9 +780,9 @@ describe('apply function', () => {
         expectedAssetKeys: [],
         expectedWarnings: [
           new Error(
-            `[copy-webpack-plugin] unable to locate 'nonexistent.txt' at '${HELPER_DIR}${
-              path.sep
-            }nonexistent.txt'`
+            `[copy-webpack-plugin] unable to locate 'nonexistent.txt' at '${normalizePath(
+              HELPER_DIR
+            )}/nonexistent.txt'`
           ),
         ],
         patterns: [
@@ -788,9 +801,9 @@ describe('apply function', () => {
         expectedAssetKeys: [],
         expectedWarnings: [
           new Error(
-            `[copy-webpack-plugin] unable to locate 'nonexistent.txt' at '${HELPER_DIR}${
-              path.sep
-            }nonexistent.txt'`
+            `[copy-webpack-plugin] unable to locate 'nonexistent.txt' at '${normalizePath(
+              HELPER_DIR
+            )}/nonexistent.txt'`
           ),
         ],
         patterns: [
@@ -1192,7 +1205,7 @@ describe('apply function', () => {
         ],
       })
         .then((compilation) => {
-          const absFrom = path.join(HELPER_DIR, 'file.txt');
+          const absFrom = normalizePath(path.join(HELPER_DIR, 'file.txt'));
 
           expect(Array.from(compilation.fileDependencies).sort()).toEqual(
             [absFrom].sort()
@@ -1226,6 +1239,7 @@ describe('apply function', () => {
           '[!]/hello.txt',
           'binextension.bin',
           'directory/directoryfile.txt',
+          'directory/nested/deep-nested/deepnested.txt',
           'directory/nested/nestedfile.txt',
           '[special?directory]/directoryfile.txt',
           '[special?directory]/(special-*file).txt',
@@ -1352,6 +1366,7 @@ describe('apply function', () => {
         expectedAssetKeys: [
           '.dottedfile',
           'directoryfile.txt',
+          'nested/deep-nested/deepnested.txt',
           'nested/nestedfile.txt',
         ],
         patterns: [
@@ -1368,6 +1383,7 @@ describe('apply function', () => {
       runEmit({
         expectedAssetKeys: [
           '/some/path/.dottedfile',
+          '/some/path/deepnested.txt',
           '/some/path/directoryfile.txt',
           '/some/path/nestedfile.txt',
         ],
@@ -1429,9 +1445,9 @@ describe('apply function', () => {
         expectedAssetKeys: [],
         expectedWarnings: [
           new Error(
-            `[copy-webpack-plugin] unable to locate 'nonexistent' at '${HELPER_DIR}${
-              path.sep
-            }nonexistent'`
+            `[copy-webpack-plugin] unable to locate 'nonexistent' at '${normalizePath(
+              HELPER_DIR
+            )}/nonexistent'`
           ),
         ],
         patterns: [
@@ -1451,6 +1467,7 @@ describe('apply function', () => {
         expectedAssetKeys: [
           '.dottedfile',
           'directoryfile.txt',
+          'nested/deep-nested/deepnested.txt',
           'nested/nestedfile.txt',
         ],
         patterns: [
@@ -1468,6 +1485,7 @@ describe('apply function', () => {
         expectedAssetKeys: [
           'newdirectory/.dottedfile',
           'newdirectory/directoryfile.txt',
+          'newdirectory/nested/deep-nested/deepnested.txt',
           'newdirectory/nested/nestedfile.txt',
         ],
         patterns: [
@@ -1483,7 +1501,10 @@ describe('apply function', () => {
 
     it("can move a directory's contents to a new directory using a pattern context", (done) => {
       runEmit({
-        expectedAssetKeys: ['newdirectory/nestedfile.txt'],
+        expectedAssetKeys: [
+          'newdirectory/deep-nested/deepnested.txt',
+          'newdirectory/nestedfile.txt',
+        ],
         patterns: [
           {
             context: 'directory',
@@ -1500,6 +1521,7 @@ describe('apply function', () => {
       runEmit({
         expectedAssetKeys: [
           'newdirectory/.dottedfile',
+          'newdirectory/deepnested.txt',
           'newdirectory/directoryfile.txt',
           'newdirectory/nestedfile.txt',
         ],
@@ -1520,6 +1542,7 @@ describe('apply function', () => {
         expectedAssetKeys: [
           '../tempdir/.dottedfile',
           '../tempdir/directoryfile.txt',
+          '../tempdir/nested/deep-nested/deepnested.txt',
           '../tempdir/nested/nestedfile.txt',
         ],
         patterns: [
@@ -1535,7 +1558,7 @@ describe('apply function', () => {
 
     it("can move a nested directory's contents to the root directory", (done) => {
       runEmit({
-        expectedAssetKeys: ['nestedfile.txt'],
+        expectedAssetKeys: ['deep-nested/deepnested.txt', 'nestedfile.txt'],
         patterns: [
           {
             from: 'directory/nested',
@@ -1548,7 +1571,10 @@ describe('apply function', () => {
 
     it("can move a nested directory's contents to a new directory", (done) => {
       runEmit({
-        expectedAssetKeys: ['newdirectory/nestedfile.txt'],
+        expectedAssetKeys: [
+          'newdirectory/deep-nested/deepnested.txt',
+          'newdirectory/nestedfile.txt',
+        ],
         patterns: [
           {
             from: 'directory/nested',
@@ -1564,7 +1590,10 @@ describe('apply function', () => {
       const absolutePath = path.resolve(HELPER_DIR, 'directory', 'nested');
 
       runEmit({
-        expectedAssetKeys: ['newdirectory/nestedfile.txt'],
+        expectedAssetKeys: [
+          'newdirectory/deep-nested/deepnested.txt',
+          'newdirectory/nestedfile.txt',
+        ],
         patterns: [
           {
             from: absolutePath,
@@ -1618,7 +1647,7 @@ describe('apply function', () => {
         ],
       })
         .then((compilation) => {
-          const absFrom = path.resolve(HELPER_DIR, 'directory');
+          const absFrom = normalizePath(path.resolve(HELPER_DIR, 'directory'));
           expect(Array.from(compilation.contextDependencies).sort()).toEqual(
             [absFrom].sort()
           );
@@ -1647,6 +1676,7 @@ describe('apply function', () => {
         expectedAssetKeys: [
           '.dottedfile',
           'directoryfile.txt',
+          'nested/deep-nested/deepnested.txt',
           'nested/nestedfile.txt',
           'tempfile1.txt',
           'tempfile2.txt',
@@ -1671,6 +1701,7 @@ describe('apply function', () => {
         expectedAssetKeys: [
           'nested/.dottedfile-79d39f',
           'nested/directoryfile-22af64.txt',
+          'nested/nested/deep-nested/deepnested-d41d8c.txt',
           'nested/nested/nestedfile-d41d8c.txt',
         ],
         patterns: [
@@ -1714,6 +1745,189 @@ describe('apply function', () => {
     });
   });
 
+  describe('with difference path segment separation', () => {
+    it('can normalize backslash path with glob in from', (done) => {
+      runEmit({
+        expectedAssetKeys: ['directory/nested/nestedfile.txt'],
+        patterns: [
+          {
+            from: {
+              glob: 'directory\\nested\\*',
+            },
+          },
+        ],
+      })
+        .then(done)
+        .catch(done);
+    });
+
+    it('can normalize backslash path with glob in from (mixed path segment separation)', (done) => {
+      runEmit({
+        expectedAssetKeys: ['directory/nested/nestedfile.txt'],
+        patterns: [
+          {
+            from: {
+              glob: 'directory/nested\\*',
+            },
+          },
+        ],
+      })
+        .then(done)
+        .catch(done);
+    });
+
+    it('can normalize backslash path with glob in from (simple)', (done) => {
+      runEmit({
+        expectedAssetKeys: ['directory/nested/nestedfile.txt'],
+        patterns: [
+          {
+            from: 'directory\\nested\\*',
+          },
+        ],
+      })
+        .then(done)
+        .catch(done);
+    });
+
+    it('can normalize mixed path segment separation with glob in from (simple)', (done) => {
+      runEmit({
+        expectedAssetKeys: ['directory/nested/nestedfile.txt'],
+        patterns: [
+          {
+            from: 'directory/nested\\*',
+          },
+        ],
+      })
+        .then(done)
+        .catch(done);
+    });
+
+    it('can normalize backslash path with file in from', (done) => {
+      runEmit({
+        expectedAssetKeys: ['nestedfile.txt'],
+        patterns: [
+          {
+            from: 'directory\\nested\\nestedfile.txt',
+          },
+        ],
+      })
+        .then(done)
+        .catch(done);
+    });
+
+    it('can normalize backslash path with file in from (mixed path segment separation)', (done) => {
+      runEmit({
+        expectedAssetKeys: ['nestedfile.txt'],
+        patterns: [
+          {
+            from: 'directory\\nested/nestedfile.txt',
+          },
+        ],
+      })
+        .then(done)
+        .catch(done);
+    });
+
+    it('can normalize backslash path with directory in from', (done) => {
+      runEmit({
+        expectedAssetKeys: ['deepnested.txt'],
+        patterns: [
+          {
+            from: 'directory\\nested\\deep-nested',
+          },
+        ],
+      })
+        .then(done)
+        .catch(done);
+    });
+
+    it('can normalize backslash path with directory in from (mixed path segment separation)', (done) => {
+      runEmit({
+        expectedAssetKeys: ['deepnested.txt'],
+        patterns: [
+          {
+            from: 'directory\\nested\\deep-nested',
+          },
+        ],
+      })
+        .then(done)
+        .catch(done);
+    });
+
+    it('can exclude path', (done) => {
+      runEmit({
+        expectedAssetKeys: [
+          '[!]/hello.txt',
+          '[special?directory]/(special-*file).txt',
+          '[special?directory]/directoryfile.txt',
+          '[special?directory]/nested/nestedfile.txt',
+        ],
+        patterns: [
+          {
+            from: '!(directory)/**/*.txt',
+          },
+        ],
+      })
+        .then(done)
+        .catch(done);
+    });
+
+    it('can exclude path with backslash path', (done) => {
+      runEmit({
+        expectedAssetKeys: [
+          '[!]/hello.txt',
+          '[special?directory]/(special-*file).txt',
+          '[special?directory]/directoryfile.txt',
+          '[special?directory]/nested/nestedfile.txt',
+        ],
+        patterns: [
+          {
+            from: '!(directory)\\**\\*.txt',
+          },
+        ],
+      })
+        .then(done)
+        .catch(done);
+    });
+
+    it('can normalize backslash in context', (done) => {
+      runEmit({
+        expectedAssetKeys: [
+          'newdirectory/deep-nested/deepnested.txt',
+          'newdirectory/nestedfile.txt',
+        ],
+        options: {
+          context: path.resolve(HELPER_DIR, 'directory\\'),
+        },
+        patterns: [
+          {
+            from: 'nested',
+            to: 'newdirectory',
+          },
+        ],
+      })
+        .then(done)
+        .catch(done);
+    });
+
+    it('can normalize backslash in context (2)', (done) => {
+      runEmit({
+        expectedAssetKeys: ['newdirectory/deepnested.txt'],
+        options: {
+          context: path.resolve(HELPER_DIR, 'directory\\nested'),
+        },
+        patterns: [
+          {
+            from: 'deep-nested',
+            to: 'newdirectory',
+          },
+        ],
+      })
+        .then(done)
+        .catch(done);
+    });
+  });
+
   describe('options', () => {
     describe('ignore', () => {
       it('ignores files when from is a file', (done) => {
@@ -1737,7 +1951,11 @@ describe('apply function', () => {
 
       it('ignores files when from is a directory', (done) => {
         runEmit({
-          expectedAssetKeys: ['.dottedfile', 'directoryfile.txt'],
+          expectedAssetKeys: [
+            '.dottedfile',
+            'directoryfile.txt',
+            'nested/deep-nested/deepnested.txt',
+          ],
           options: {
             ignore: ['*/nestedfile.*'],
           },
@@ -1775,6 +1993,7 @@ describe('apply function', () => {
             'file.txt',
             'file.txt.gz',
             'directory/directoryfile.txt',
+            'directory/nested/deep-nested/deepnested.txt',
             'directory/nested/nestedfile.txt',
             '[special?directory]/directoryfile.txt',
             '[special?directory]/(special-*file).txt',
@@ -1904,7 +2123,10 @@ describe('apply function', () => {
     describe('context', () => {
       it('overrides webpack config context with absolute path', (done) => {
         runEmit({
-          expectedAssetKeys: ['newdirectory/nestedfile.txt'],
+          expectedAssetKeys: [
+            'newdirectory/deep-nested/deepnested.txt',
+            'newdirectory/nestedfile.txt',
+          ],
           options: {
             context: path.resolve(HELPER_DIR, 'directory'),
           },
@@ -1921,7 +2143,10 @@ describe('apply function', () => {
 
       it('overrides webpack config context with relative path', (done) => {
         runEmit({
-          expectedAssetKeys: ['newdirectory/nestedfile.txt'],
+          expectedAssetKeys: [
+            'newdirectory/deep-nested/deepnested.txt',
+            'newdirectory/nestedfile.txt',
+          ],
           options: {
             context: 'directory',
           },
@@ -1938,7 +2163,10 @@ describe('apply function', () => {
 
       it('is overridden by pattern context', (done) => {
         runEmit({
-          expectedAssetKeys: ['newdirectory/nestedfile.txt'],
+          expectedAssetKeys: [
+            'newdirectory/deep-nested/deepnested.txt',
+            'newdirectory/nestedfile.txt',
+          ],
           options: {
             context: 'directory',
           },
@@ -2008,6 +2236,7 @@ describe('apply function', () => {
           expectedAssetKeys: [
             '.dottedfile',
             'directoryfile.txt',
+            'nested/deep-nested/deepnested.txt',
             'nested/nestedfile.txt',
           ],
           expectedAssetContent: {
diff --git a/test/helpers/directory/nested/deep-nested/deepnested.txt b/test/helpers/directory/nested/deep-nested/deepnested.txt
new file mode 100644
index 00000000..e69de29b