diff --git a/lib/heroku-config-vars.js b/lib/heroku-config-vars.js
index dfd9b86..f3b764d 100644
--- a/lib/heroku-config-vars.js
+++ b/lib/heroku-config-vars.js
@@ -49,7 +49,7 @@ class HerokuConfigVars {
 	*/
 	set (patch) {
 		return this.makeApiCall({
-			method: 'patch',
+			method: 'PATCH',
 			body: JSON.stringify(patch)
 		});
 	}
diff --git a/lib/review-apps.js b/lib/review-apps.js
index 1a5f003..4d5a1b1 100644
--- a/lib/review-apps.js
+++ b/lib/review-apps.js
@@ -125,7 +125,7 @@ const deleteReviewAppAndThrowError = async ({ reviewApp, commit, appId }) => {
 
 		const headers = await herokuHeaders({ useReviewAppApi: true });
 
-		await performFetch(getReviewAppUrl(reviewApp.id), { headers, method: 'delete' });
+		await performFetch(getReviewAppUrl(reviewApp.id), { headers, method: 'DELETE' });
 
 	} catch (error) {
 
@@ -261,7 +261,7 @@ const createReviewApp = async ({ pipelineId, repoName, commit, branch, githubTok
 		}
 	};
 
-	const response = await fetch(REVIEW_APPS_URL, { headers, method: 'post', body: JSON.stringify(body) });
+	const response = await fetch(REVIEW_APPS_URL, { headers, method: 'POST', body: JSON.stringify(body) });
 
 	return response;