diff --git a/Backend/src/main/java/com/mobilecomputing/pecunia/controller/TripController.java b/Backend/src/main/java/com/mobilecomputing/pecunia/controller/TripController.java
index e573d9aedf4a21caf9be8a0ce15b1f0d801725aa..edf62287867bfd5b67209df65efe62815f702c61 100644
--- a/Backend/src/main/java/com/mobilecomputing/pecunia/controller/TripController.java
+++ b/Backend/src/main/java/com/mobilecomputing/pecunia/controller/TripController.java
@@ -15,7 +15,7 @@ public class TripController {
     @GetMapping("/getTripById")
     public String getTripById(@RequestParam String id){
 
-        return String.valueOf(tripRepository.findById(new ObjectId(id)));
+        return String.valueOf(tripRepository.findById(id));
     }
 
     @GetMapping("/getAllTrips")
diff --git a/Backend/src/main/java/com/mobilecomputing/pecunia/controller/UserController.java b/Backend/src/main/java/com/mobilecomputing/pecunia/controller/UserController.java
index 6e302bed566703f8891644ecbd862b719c6b3a1d..6661b516c6a220545876adb3509ae2a883e89714 100644
--- a/Backend/src/main/java/com/mobilecomputing/pecunia/controller/UserController.java
+++ b/Backend/src/main/java/com/mobilecomputing/pecunia/controller/UserController.java
@@ -17,7 +17,7 @@ public class UserController {
 
     @GetMapping("/getById")
     public String getUserById(@RequestParam String id){
-        return String.valueOf(userRepository.findById(new ObjectId(id)));
+        return String.valueOf(userRepository.findById(id));
     }
 
     @GetMapping("/getAll")
@@ -38,6 +38,6 @@ public class UserController {
 
     @DeleteMapping("/deleteUser")
     public void deleteUser(@RequestParam String eMail){
-        userRepository.deleteById(new ObjectId(eMail));
+        userRepository.deleteById(eMail);
     }
 }
diff --git a/Backend/src/main/java/com/mobilecomputing/pecunia/repository/TripRepository.java b/Backend/src/main/java/com/mobilecomputing/pecunia/repository/TripRepository.java
index e540fa0d3b60d2d067d824be04d258e6dcfb8979..a79b6d7cbc468f1b2ad2f75f20d88139d1299b0f 100644
--- a/Backend/src/main/java/com/mobilecomputing/pecunia/repository/TripRepository.java
+++ b/Backend/src/main/java/com/mobilecomputing/pecunia/repository/TripRepository.java
@@ -4,6 +4,6 @@ import com.mobilecomputing.pecunia.model.Trip;
 import org.bson.types.ObjectId;
 import org.springframework.data.repository.CrudRepository;
 
-public interface TripRepository extends CrudRepository<Trip, ObjectId> {
+public interface TripRepository extends CrudRepository<Trip, String> {
 
 }
diff --git a/Backend/src/main/java/com/mobilecomputing/pecunia/repository/UserRepository.java b/Backend/src/main/java/com/mobilecomputing/pecunia/repository/UserRepository.java
index 1d9dfabcb7b2915ba39995e218a0c7db0bda0626..d9a18b603f1a3f0cbccbda46b7ccbdea961db8fe 100644
--- a/Backend/src/main/java/com/mobilecomputing/pecunia/repository/UserRepository.java
+++ b/Backend/src/main/java/com/mobilecomputing/pecunia/repository/UserRepository.java
@@ -4,5 +4,5 @@ import com.mobilecomputing.pecunia.model.ApplicationUser;
 import org.bson.types.ObjectId;
 import org.springframework.data.repository.CrudRepository;
 
-public interface UserRepository extends CrudRepository<ApplicationUser, ObjectId> {
+public interface UserRepository extends CrudRepository<ApplicationUser, String> {
 }
diff --git a/Backend/src/main/java/com/mobilecomputing/pecunia/security/UserDetailsServiceImpl.java b/Backend/src/main/java/com/mobilecomputing/pecunia/security/UserDetailsServiceImpl.java
index d15055b3fa0efbc0fbf24bbf77e410d41851dc46..dca1b95027fec0e0a2c78ccdcbddeaa866a76521 100644
--- a/Backend/src/main/java/com/mobilecomputing/pecunia/security/UserDetailsServiceImpl.java
+++ b/Backend/src/main/java/com/mobilecomputing/pecunia/security/UserDetailsServiceImpl.java
@@ -25,7 +25,7 @@ public class UserDetailsServiceImpl implements UserDetailsService {
     @Override
     public UserDetails loadUserByUsername(String userEmail) throws UsernameNotFoundException {
         System.out.println("loadbyUsername");
-        Optional<ApplicationUser> user = userRepository.findById(new ObjectId(userEmail));
+        Optional<ApplicationUser> user = userRepository.findById(userEmail);
         if(user ==null){
             throw new UsernameNotFoundException(user.toString());
         }