diff --git a/std/path/_constants.ts b/std/path/_constants.ts
index ae0aac1846..186c32ab53 100644
--- a/std/path/_constants.ts
+++ b/std/path/_constants.ts
@@ -1,7 +1,6 @@
 // Copyright the Browserify authors. MIT License.
 // Ported from https://github.com/browserify/path-browserify/
-
-const { build } = Deno;
+/** This module is browser compatible. */
 
 // Alphabet chars.
 export const CHAR_UPPERCASE_A = 65; /* A */
@@ -48,7 +47,14 @@ export const CHAR_EQUAL = 61; /* = */
 export const CHAR_0 = 48; /* 0 */
 export const CHAR_9 = 57; /* 9 */
 
-const isWindows = build.os == "windows";
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+const navigator = (globalThis as any).navigator;
 
-export const SEP = isWindows ? "\\" : "/";
-export const SEP_PATTERN = isWindows ? /[\\/]+/ : /\/+/;
+let isWindows = false;
+if (globalThis.Deno != null) {
+  isWindows = Deno.build.os == "windows";
+} else if (navigator?.appVersion != null) {
+  isWindows = navigator.appVersion.includes("Win");
+}
+
+export { isWindows };
diff --git a/std/path/_globrex.ts b/std/path/_globrex.ts
index 2b3af14ad0..6ad297d864 100644
--- a/std/path/_globrex.ts
+++ b/std/path/_globrex.ts
@@ -1,8 +1,10 @@
 // This file is ported from globrex@0.1.2
 // MIT License
 // Copyright (c) 2018 Terkel Gjervig Nielsen
+/** This module is browser compatible. */
+
+import { isWindows as isWin } from "./_constants.ts";
 
-const isWin = Deno.build.os === "windows";
 const SEP = isWin ? `(?:\\\\|\\/)` : `\\/`;
 const SEP_ESC = isWin ? `\\\\` : `/`;
 const SEP_RAW = isWin ? `\\` : `/`;
diff --git a/std/path/interface.ts b/std/path/_interface.ts
similarity index 93%
rename from std/path/interface.ts
rename to std/path/_interface.ts
index b31c89ea73..6c82c9c35c 100644
--- a/std/path/interface.ts
+++ b/std/path/_interface.ts
@@ -1,3 +1,5 @@
+/** This module is browser compatible. */
+
 /**
  * A parsed path object generated by path.parse() or consumed by path.format().
  */
diff --git a/std/path/_util.ts b/std/path/_util.ts
index 2776303cb6..8ae40373b2 100644
--- a/std/path/_util.ts
+++ b/std/path/_util.ts
@@ -1,7 +1,8 @@
 // Copyright the Browserify authors. MIT License.
 // Ported from https://github.com/browserify/path-browserify/
+/** This module is browser compatible. */
 
-import { FormatInputPathObject } from "./interface.ts";
+import { FormatInputPathObject } from "./_interface.ts";
 import {
   CHAR_UPPERCASE_A,
   CHAR_LOWERCASE_A,
diff --git a/std/path/common.ts b/std/path/common.ts
index e0e51ef239..01470105ca 100644
--- a/std/path/common.ts
+++ b/std/path/common.ts
@@ -1,4 +1,5 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+/** This module is browser compatible. */
 
 import { SEP } from "./separator.ts";
 
diff --git a/std/path/glob.ts b/std/path/glob.ts
index 80672579d2..34fc213f62 100644
--- a/std/path/glob.ts
+++ b/std/path/glob.ts
@@ -1,3 +1,6 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+/** This module is browser compatible. */
+
 import { SEP, SEP_PATTERN } from "./separator.ts";
 import { globrex } from "./_globrex.ts";
 import { join, normalize } from "./mod.ts";
diff --git a/std/path/mod.ts b/std/path/mod.ts
index 9cb7f1edb2..0b4156e699 100644
--- a/std/path/mod.ts
+++ b/std/path/mod.ts
@@ -1,11 +1,11 @@
 // Copyright the Browserify authors. MIT License.
 // Ported mostly from https://github.com/browserify/path-browserify/
+/** This module is browser compatible. */
 
+import { isWindows } from "./_constants.ts";
 import * as _win32 from "./win32.ts";
 import * as _posix from "./posix.ts";
 
-const isWindows = Deno.build.os == "windows";
-
 const path = isWindows ? _win32 : _posix;
 
 export const win32 = _win32;
@@ -29,5 +29,5 @@ export const {
 
 export * from "./common.ts";
 export { SEP, SEP_PATTERN } from "./separator.ts";
-export * from "./interface.ts";
+export * from "./_interface.ts";
 export * from "./glob.ts";
diff --git a/std/path/posix.ts b/std/path/posix.ts
index e88eb3f973..365232e336 100644
--- a/std/path/posix.ts
+++ b/std/path/posix.ts
@@ -1,8 +1,8 @@
 // Copyright the Browserify authors. MIT License.
 // Ported from https://github.com/browserify/path-browserify/
+/** This module is browser compatible. */
 
-const { cwd } = Deno;
-import { FormatInputPathObject, ParsedPath } from "./interface.ts";
+import { FormatInputPathObject, ParsedPath } from "./_interface.ts";
 import { CHAR_DOT, CHAR_FORWARD_SLASH } from "./_constants.ts";
 
 import {
@@ -24,7 +24,12 @@ export function resolve(...pathSegments: string[]): string {
     let path: string;
 
     if (i >= 0) path = pathSegments[i];
-    else path = cwd();
+    else {
+      if (globalThis.Deno == null) {
+        throw new TypeError("Resolved a relative path without a CWD.");
+      }
+      path = Deno.cwd();
+    }
 
     assertPath(path);
 
diff --git a/std/path/separator.ts b/std/path/separator.ts
index fb990b8086..4b54ad4384 100644
--- a/std/path/separator.ts
+++ b/std/path/separator.ts
@@ -1,4 +1,7 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
-const isWindows = Deno.build.os == "windows";
+/** This module is browser compatible. */
+
+import { isWindows } from "./_constants.ts";
+
 export const SEP = isWindows ? "\\" : "/";
 export const SEP_PATTERN = isWindows ? /[\\/]+/ : /\/+/;
diff --git a/std/path/win32.ts b/std/path/win32.ts
index 0557b3768e..f556c5b736 100644
--- a/std/path/win32.ts
+++ b/std/path/win32.ts
@@ -1,8 +1,8 @@
 // Copyright the Browserify authors. MIT License.
 // Ported from https://github.com/browserify/path-browserify/
+/** This module is browser compatible. */
 
-const { cwd, env } = Deno;
-import { FormatInputPathObject, ParsedPath } from "./interface.ts";
+import { FormatInputPathObject, ParsedPath } from "./_interface.ts";
 import {
   CHAR_DOT,
   CHAR_BACKWARD_SLASH,
@@ -32,14 +32,20 @@ export function resolve(...pathSegments: string[]): string {
     if (i >= 0) {
       path = pathSegments[i];
     } else if (!resolvedDevice) {
-      path = cwd();
+      if (globalThis.Deno == null) {
+        throw new TypeError("Resolved a drive-letter-less path without a CWD.");
+      }
+      path = Deno.cwd();
     } else {
+      if (globalThis.Deno == null) {
+        throw new TypeError("Resolved a relative path without a CWD.");
+      }
       // Windows has the concept of drive-specific current working
       // directories. If we've resolved a drive letter but not yet an
       // absolute path, get cwd for that drive, or the process cwd if
       // the drive cwd is not available. We're sure the device is not
       // a UNC path at this points, because UNC paths are always absolute.
-      path = env.get(`=${resolvedDevice}`) || cwd();
+      path = Deno.env.get(`=${resolvedDevice}`) || Deno.cwd();
 
       // Verify that a cwd was found and that it actually points
       // to our drive. If not, default to the drive's root.