diff --git a/Changelog.md b/Changelog.md
index a19d42e7..cbb2c655 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Added `--base-url` option.
+  #65 by @kean.
+
 ## [1.0.0-beta.2] - 2020-04-08
 
 ### Changed
diff --git a/Sources/swift-doc/Subcommands/Generate.swift b/Sources/swift-doc/Subcommands/Generate.swift
index 9f91ef34..707cb9ba 100644
--- a/Sources/swift-doc/Subcommands/Generate.swift
+++ b/Sources/swift-doc/Subcommands/Generate.swift
@@ -29,6 +29,11 @@ extension SwiftDoc {
                     default: .commonmark,
                     help: "The output format")
             var format: Format
+
+            @Option(name: .customLong("base-url"),
+                    default: "/",
+                    help: "The base URL used for all relative URLs in generated documents.")
+            var baseURL: String
         }
 
         static var configuration = CommandConfiguration(abstract: "Generates Swift documentation")
@@ -79,7 +84,7 @@ extension SwiftDoc {
                     }
 
                     let url = outputDirectoryURL.appendingPathComponent(filename)
-                    try page.write(to: url, format: format)
+                    try page.write(to: url, format: format, baseURL: options.baseURL)
                 } else {
                     switch format {
                     case .commonmark:
@@ -102,7 +107,7 @@ extension SwiftDoc {
                         }
 
                         let url = outputDirectoryURL.appendingPathComponent(filename)
-                        try $0.value.write(to: url, format: format)
+                        try $0.value.write(to: url, format: format, baseURL: options.baseURL)
                     }
                 }
             } catch {
diff --git a/Sources/swift-doc/Supporting Types/Components/Relationships.swift b/Sources/swift-doc/Supporting Types/Components/Relationships.swift
index 5ef8f7cf..c442b414 100644
--- a/Sources/swift-doc/Supporting Types/Components/Relationships.swift	
+++ b/Sources/swift-doc/Supporting Types/Components/Relationships.swift	
@@ -113,7 +113,7 @@ struct Relationships: Component {
                                 """#
                             } else {
                                 return #"""
-                                <dt class="\#(descriptor)"><code><a href="/\#(path(for: symbol))">\#(symbol.id)</a></code></dt>
+                                <dt class="\#(descriptor)"><code><a href="\#(path(for: symbol))">\#(symbol.id)</a></code></dt>
                                 <dd>\#(commonmark: symbol.documentation?.summary ?? "")</dd>
                                 """#
                             }
diff --git a/Sources/swift-doc/Supporting Types/Helpers.swift b/Sources/swift-doc/Supporting Types/Helpers.swift
index 92962c96..695509b7 100644
--- a/Sources/swift-doc/Supporting Types/Helpers.swift	
+++ b/Sources/swift-doc/Supporting Types/Helpers.swift	
@@ -12,7 +12,7 @@ public func linkCodeElements(of html: String, for symbol: Symbol, in module: Mod
             let candidate = candidates.filter({ $0 != symbol }).first
         {
             let a = Element(name: "a")
-            a["href"] = "/" + path(for: candidate)
+            a["href"] = path(for: candidate)
             element.wrap(inside: a)
         }
     }
diff --git a/Sources/swift-doc/Supporting Types/Layout.swift b/Sources/swift-doc/Supporting Types/Layout.swift
index 74e5e4e6..4baef7e4 100644
--- a/Sources/swift-doc/Supporting Types/Layout.swift	
+++ b/Sources/swift-doc/Supporting Types/Layout.swift	
@@ -1,7 +1,7 @@
 import HypertextLiteral
 import Foundation
 
-func layout(_ page: Page) -> HTML {
+func layout(_ page: Page, baseURL: String) -> HTML {
     let html = page.html
 
     return #"""
@@ -11,13 +11,14 @@ func layout(_ page: Page) -> HTML {
         <meta charset="UTF-8">
         <meta name="viewport" content="width=device-width, initial-scale=1.0">
         <title>\#(page.module.name) - \#(page.title)</title>
+        <base href="\#(baseURL)"/>
         <style type="text/css">
         \#(unsafeUnescaped: css)
         </style>
     </head>
     <body>
         <header>
-            <a href="/">
+            <a href="\#(baseURL)">
                 <strong>
                     \#(page.module.name)
                 </strong>
diff --git a/Sources/swift-doc/Supporting Types/Page.swift b/Sources/swift-doc/Supporting Types/Page.swift
index 6ed37aa8..fec3c7bb 100644
--- a/Sources/swift-doc/Supporting Types/Page.swift	
+++ b/Sources/swift-doc/Supporting Types/Page.swift	
@@ -19,13 +19,13 @@ extension Page {
 }
 
 extension Page {
-    func write(to url: URL, format: SwiftDoc.Generate.Format) throws {
+    func write(to url: URL, format: SwiftDoc.Generate.Format, baseURL: String) throws {
         let data: Data?
         switch format {
         case .commonmark:
             data = document.render(format: .commonmark).data(using: .utf8)
         case .html:
-            data = layout(self).description.data(using: .utf8)
+            data = layout(self, baseURL: baseURL).description.data(using: .utf8)
         }
 
         let fileManager = FileManager.default