diff --git a/src/PdfCreator.ts b/src/PdfCreator.ts
index f929c83..d123721 100644
--- a/src/PdfCreator.ts
+++ b/src/PdfCreator.ts
@@ -122,11 +122,6 @@ export class PdfCreator {
         if (runners.length == 1 && Object.keys(runners[0]).length == 0) {
             runners[0] = this.generateEmptyRunner();
         }
-        for (var i = 1; i < PdfCreator.contractsPerRunner; i++) {
-            runners = runners.reduce(function (res, current, index, array) {
-                return res.concat([current, current]);
-            }, []);
-        }
         if (runners.length > 50) {
             let pdf_promises = new Array<Promise<Buffer>>();
             let i, j;
@@ -137,6 +132,11 @@ export class PdfCreator {
             const pdfs = await Promise.all(pdf_promises);
             return await this.mergePdfs(pdfs);
         }
+        for (var i = 1; i < PdfCreator.contractsPerRunner; i++) {
+            runners = runners.reduce(function (res, current, index, array) {
+                return res.concat([current, current]);
+            }, []);
+        }
         await i18next.changeLanguage(locale);
         const template_source = fs.readFileSync(`${this.templateDir}/sponsoring_contract.html`, 'utf8');
         const template = Handlebars.compile(template_source);
@@ -179,14 +179,13 @@ export class PdfCreator {
      */
     public async generateRunnerCertficates(runners: CertificateRunner[], locale: string = "en"): Promise<Buffer> {
         if (runners.length > 50) {
-            let pdf_promises = new Array<Promise<Buffer>>();
+            let pdf_promises = new Array<Buffer>();
             let i, j;
             for (i = 0, j = runners.length; i < j; i += 50) {
                 let chunk = runners.slice(i, i + 50);
-                pdf_promises.push(this.generateRunnerCertficates(chunk, locale));
+                pdf_promises.push(await this.generateRunnerCertficates(chunk, locale));
             }
-            const pdfs = await Promise.all(pdf_promises);
-            return await this.mergePdfs(pdfs);
+            return await this.mergePdfs(pdf_promises);
         }
         await i18next.changeLanguage(locale);
         const template_source = fs.readFileSync(`${this.templateDir}/runner_certificate.html`, 'utf8');