diff --git a/README.md b/README.md
index bdbfb9c..66f6219 100644
--- a/README.md
+++ b/README.md
@@ -107,9 +107,10 @@ Project maintained on GitHub at [automattic/wordpress-activitypub](https://githu
 
 ### Next ###
 
-* Compatibility: allow deactivating blocks registered by the plugin.
-* Compatibility: avoid Fatal Errors when using ClassicPress.
-* Fixed: fix a typo in a hook name.
+* Compatibility: allow deactivating blocks registered by the plugin
+* Compatibility: avoid Fatal Errors when using ClassicPress
+* Fixed: fix a typo in a hook name
+* Fixed: a problem with signatures when running WordPress in a sub-path
 
 ### 1.0.0 ###
 
diff --git a/includes/class-signature.php b/includes/class-signature.php
index 1b29d4c..10cbf39 100644
--- a/includes/class-signature.php
+++ b/includes/class-signature.php
@@ -238,6 +238,15 @@ class Signature {
 			} else {
 				$route = '/' . rest_get_url_prefix() . '/' . ltrim( $request->get_route(), '/' );
 			}
+
+			// fix route for subdirectory installs
+			$path = wp_parse_url( get_home_url(), PHP_URL_PATH );
+			$path = trim( $path, '/' );
+
+			if ( $path ) {
+				$route = '/' . $path . $route;
+			}
+
 			$headers = $request->get_headers();
 			$headers['(request-target)'][0] = strtolower( $request->get_method() ) . ' ' . $route;
 		} else {
diff --git a/readme.txt b/readme.txt
index 9f1fed6..f9303c3 100644
--- a/readme.txt
+++ b/readme.txt
@@ -107,9 +107,10 @@ Project maintained on GitHub at [automattic/wordpress-activitypub](https://githu
 
 = Next =
 
-* Compatibility: allow deactivating blocks registered by the plugin.
-* Compatibility: avoid Fatal Errors when using ClassicPress.
-* Fixed: fix a typo in a hook name.
+* Compatibility: allow deactivating blocks registered by the plugin
+* Compatibility: avoid Fatal Errors when using ClassicPress
+* Fixed: fix a typo in a hook name
+* Fixed: a problem with signatures when running WordPress in a sub-path
 
 = 1.0.0 =