diff --git a/NodeApp/src/managers/DojoBackendManager.ts b/NodeApp/src/managers/DojoBackendManager.ts
index b19436b7a69a30cee915406484607d34f04e186a..cf26bd76041af8ebcfaeb26177ea892b28435bf0 100644
--- a/NodeApp/src/managers/DojoBackendManager.ts
+++ b/NodeApp/src/managers/DojoBackendManager.ts
@@ -93,7 +93,7 @@ class DojoBackendManager {
             const response = await axios.post<DojoBackendResponse<Assignment>>(this.getApiUrl(ApiRoute.ASSIGNMENT_CREATE), Object.assign({
                                                                                                                                              name     : name,
                                                                                                                                              members  : JSON.stringify(members),
-                                                                                                                                             useSonar : sonar
+                                                                                                                                             useSonar : String(sonar)
                                                                                                                                          }, templateIdOrNamespace ? { template: templateIdOrNamespace } : {}));
 
             if ( verbose ) {