diff --git a/README.md b/README.md
index 1f0c6f2..18b5742 100644
--- a/README.md
+++ b/README.md
@@ -114,6 +114,7 @@ Project maintained on GitHub at [automattic/wordpress-activitypub](https://githu
 * Improved: loading of shortcodes
 * Updated: caching of followers
 * Updated: Application-User is no longer "indexable"
+* Updated: more consistent usage of the `application/activity+json` Content-Type
 
 ### 1.0.7 ###
 
diff --git a/includes/rest/class-collection.php b/includes/rest/class-collection.php
index 5fa585d..2e6522e 100644
--- a/includes/rest/class-collection.php
+++ b/includes/rest/class-collection.php
@@ -117,7 +117,10 @@ class Collection {
 			);
 		}
 
-		return new WP_REST_Response( $response, 200 );
+		$rest_response = new WP_REST_Response( $response, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
 	}
 
 	/**
@@ -168,7 +171,10 @@ class Collection {
 			$response['orderedItems'][] = Post::transform( $post )->to_object()->to_array();
 		}
 
-		return new WP_REST_Response( $response, 200 );
+		$rest_response = new WP_REST_Response( $response, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
 	}
 
 	/**
@@ -192,7 +198,10 @@ class Collection {
 			$response['orderedItems'][] = $user->get_url();
 		}
 
-		return new WP_REST_Response( $response, 200 );
+		$rest_response = new WP_REST_Response( $response, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
 	}
 
 	/**
diff --git a/includes/rest/class-followers.php b/includes/rest/class-followers.php
index b7be9d0..71e4840 100644
--- a/includes/rest/class-followers.php
+++ b/includes/rest/class-followers.php
@@ -103,10 +103,10 @@ class Followers {
 			$data['followers']
 		);
 
-		$response = new WP_REST_Response( $json, 200 );
-		$response->header( 'Content-Type', 'application/activity+json' );
+		$rest_response = new WP_REST_Response( $json, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
 
-		return $response;
+		return $rest_response;
 	}
 
 	/**
diff --git a/includes/rest/class-following.php b/includes/rest/class-following.php
index 33bdf65..b591ab6 100644
--- a/includes/rest/class-following.php
+++ b/includes/rest/class-following.php
@@ -79,10 +79,10 @@ class Following {
 
 		$json->first = $json->partOf; // phpcs:ignore
 
-		$response = new \WP_REST_Response( $json, 200 );
-		$response->header( 'Content-Type', 'application/activity+json' );
+		$rest_response = new WP_REST_Response( $json, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
 
-		return $response;
+		return $rest_response;
 	}
 
 	/**
diff --git a/includes/rest/class-inbox.php b/includes/rest/class-inbox.php
index 9c5961a..747290e 100644
--- a/includes/rest/class-inbox.php
+++ b/includes/rest/class-inbox.php
@@ -109,11 +109,10 @@ class Inbox {
 		 */
 		\do_action( 'activitypub_inbox_post' );
 
-		$response = new WP_REST_Response( $json, 200 );
+		$rest_response = new WP_REST_Response( $json, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
 
-		$response->header( 'Content-Type', 'application/activity+json' );
-
-		return $response;
+		return $rest_response;
 	}
 
 	/**
@@ -138,7 +137,10 @@ class Inbox {
 		\do_action( 'activitypub_inbox', $data, $user->get__id(), $type );
 		\do_action( "activitypub_inbox_{$type}", $data, $user->get__id() );
 
-		return new WP_REST_Response( array(), 202 );
+		$rest_response = new WP_REST_Response( array(), 202 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
 	}
 
 	/**
@@ -183,7 +185,10 @@ class Inbox {
 			\do_action( "activitypub_inbox_{$type}", $data, $user->ID );
 		}
 
-		return new WP_REST_Response( array(), 202 );
+		$rest_response = new WP_REST_Response( array(), 202 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
 	}
 
 	/**
diff --git a/includes/rest/class-outbox.php b/includes/rest/class-outbox.php
index eb35e86..d640d17 100644
--- a/includes/rest/class-outbox.php
+++ b/includes/rest/class-outbox.php
@@ -123,11 +123,10 @@ class Outbox {
 		 */
 		\do_action( 'activitypub_outbox_post' );
 
-		$response = new WP_REST_Response( $json, 200 );
+		$rest_response = new WP_REST_Response( $json, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
 
-		$response->header( 'Content-Type', 'application/activity+json' );
-
-		return $response;
+		return $rest_response;
 	}
 
 	/**
diff --git a/includes/rest/class-server.php b/includes/rest/class-server.php
index a8706ea..8239168 100644
--- a/includes/rest/class-server.php
+++ b/includes/rest/class-server.php
@@ -54,11 +54,10 @@ class Server {
 
 		$json = $user->to_array();
 
-		$response = new WP_REST_Response( $json, 200 );
+		$rest_response = new WP_REST_Response( $json, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
 
-		$response->header( 'Content-Type', 'application/activity+json' );
-
-		return $response;
+		return $rest_response;
 	}
 
 	/**
diff --git a/includes/rest/class-users.php b/includes/rest/class-users.php
index 31a92dd..9fb10ba 100644
--- a/includes/rest/class-users.php
+++ b/includes/rest/class-users.php
@@ -95,10 +95,10 @@ class Users {
 
 		$json = $user->to_array();
 
-		$response = new WP_REST_Response( $json, 200 );
-		$response->header( 'Content-Type', 'application/activity+json' );
+		$rest_response = new WP_REST_Response( $json, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
 
-		return $response;
+		return $rest_response;
 	}
 
 
diff --git a/readme.txt b/readme.txt
index 9b0b1b9..848a213 100644
--- a/readme.txt
+++ b/readme.txt
@@ -114,6 +114,7 @@ Project maintained on GitHub at [automattic/wordpress-activitypub](https://githu
 * Improved: loading of shortcodes
 * Updated: caching of followers
 * Updated: Application-User is no longer "indexable"
+* Updated: more consistent usage of the `application/activity+json` Content-Type
 
 = 1.0.7 =