diff --git a/crates/trusted-server-core/src/request_signing/endpoints.rs b/crates/trusted-server-core/src/request_signing/endpoints.rs
index 032a6fc5..1db457f4 100644
--- a/crates/trusted-server-core/src/request_signing/endpoints.rs
+++ b/crates/trusted-server-core/src/request_signing/endpoints.rs
@@ -48,7 +48,7 @@ pub fn handle_trusted_server_discovery(
 
     Ok(Response::from_status(200)
         .with_content_type(fastly::mime::APPLICATION_JSON)
-        .with_body_text_plain(&json))
+        .with_body(json))
 }
 
 #[derive(Debug, Deserialize, Serialize)]
@@ -118,7 +118,7 @@ pub fn handle_verify_signature(
 
     Ok(Response::from_status(200)
         .with_content_type(fastly::mime::APPLICATION_JSON)
-        .with_body_text_plain(&response_json))
+        .with_body(response_json))
 }
 
 #[derive(Debug, Deserialize, Serialize)]
@@ -199,7 +199,7 @@ pub fn handle_rotate_key(
 
             Ok(Response::from_status(200)
                 .with_content_type(fastly::mime::APPLICATION_JSON)
-                .with_body_text_plain(&response_json))
+                .with_body(response_json))
         }
         Err(e) => {
             let response = RotateKeyResponse {
@@ -220,7 +220,7 @@ pub fn handle_rotate_key(
 
             Ok(Response::from_status(500)
                 .with_content_type(fastly::mime::APPLICATION_JSON)
-                .with_body_text_plain(&response_json))
+                .with_body(response_json))
         }
     }
 }
@@ -305,7 +305,7 @@ pub fn handle_deactivate_key(
 
             Ok(Response::from_status(200)
                 .with_content_type(fastly::mime::APPLICATION_JSON)
-                .with_body_text_plain(&response_json))
+                .with_body(response_json))
         }
         Err(e) => {
             let response = DeactivateKeyResponse {
@@ -329,7 +329,7 @@ pub fn handle_deactivate_key(
 
             Ok(Response::from_status(500)
                 .with_content_type(fastly::mime::APPLICATION_JSON)
-                .with_body_text_plain(&response_json))
+                .with_body(response_json))
         }
     }
 }
@@ -366,6 +366,11 @@ mod tests {
         let mut resp =
             handle_verify_signature(&settings, req).expect("should handle verification request");
         assert_eq!(resp.get_status(), StatusCode::OK);
+        assert_eq!(
+            resp.get_content_type(),
+            Some(fastly::mime::APPLICATION_JSON),
+            "should return application/json content type"
+        );
 
         // Parse response
         let resp_body = resp.take_body_str();
@@ -403,6 +408,11 @@ mod tests {
         let mut resp =
             handle_verify_signature(&settings, req).expect("should handle verification request");
         assert_eq!(resp.get_status(), StatusCode::OK);
+        assert_eq!(
+            resp.get_content_type(),
+            Some(fastly::mime::APPLICATION_JSON),
+            "should return application/json content type"
+        );
 
         // Parse response
         let resp_body = resp.take_body_str();
@@ -584,6 +594,11 @@ mod tests {
         match result {
             Ok(mut resp) => {
                 assert_eq!(resp.get_status(), StatusCode::OK);
+                assert_eq!(
+                    resp.get_content_type(),
+                    Some(fastly::mime::APPLICATION_JSON),
+                    "should return application/json content type"
+                );
                 let body = resp.take_body_str();
 
                 // Parse the discovery document