diff --git a/backend/internal/controller/oidc_controller.go b/backend/internal/controller/oidc_controller.go
index c95d6fa..943e356 100644
--- a/backend/internal/controller/oidc_controller.go
+++ b/backend/internal/controller/oidc_controller.go
@@ -1,13 +1,14 @@
 package controller
 
 import (
-	"github.com/pocket-id/pocket-id/backend/internal/common"
-	"github.com/pocket-id/pocket-id/backend/internal/utils/cookie"
 	"log"
 	"net/http"
 	"net/url"
 	"strings"
 
+	"github.com/pocket-id/pocket-id/backend/internal/common"
+	"github.com/pocket-id/pocket-id/backend/internal/utils/cookie"
+
 	"github.com/gin-gonic/gin"
 	"github.com/pocket-id/pocket-id/backend/internal/dto"
 	"github.com/pocket-id/pocket-id/backend/internal/middleware"
@@ -149,7 +150,7 @@ func (oc *OidcController) EndSessionHandler(c *gin.Context) {
 	if err != nil {
 		// If the validation fails, the user has to confirm the logout manually and doesn't get redirected
 		log.Printf("Error getting logout callback URL, the user has to confirm the logout manually: %v", err)
-		c.Redirect(http.StatusFound, common.EnvConfig.AppURL+"/logout")
+		c.Redirect(http.StatusFound, utils.GetAbsoluteURL(common.EnvConfig.AppURL, "/logout"))
 		return
 	}
 
diff --git a/backend/internal/controller/well_known_controller.go b/backend/internal/controller/well_known_controller.go
index 3672d85..c891ed8 100644
--- a/backend/internal/controller/well_known_controller.go
+++ b/backend/internal/controller/well_known_controller.go
@@ -6,6 +6,7 @@ import (
 	"github.com/gin-gonic/gin"
 	"github.com/pocket-id/pocket-id/backend/internal/common"
 	"github.com/pocket-id/pocket-id/backend/internal/service"
+	"github.com/pocket-id/pocket-id/backend/internal/utils"
 )
 
 func NewWellKnownController(group *gin.RouterGroup, jwtService *service.JwtService) {
@@ -32,11 +33,11 @@ func (wkc *WellKnownController) openIDConfigurationHandler(c *gin.Context) {
 	appUrl := common.EnvConfig.AppURL
 	config := map[string]interface{}{
 		"issuer":                                appUrl,
-		"authorization_endpoint":                appUrl + "/authorize",
-		"token_endpoint":                        appUrl + "/api/oidc/token",
-		"userinfo_endpoint":                     appUrl + "/api/oidc/userinfo",
-		"end_session_endpoint":                  appUrl + "/api/oidc/end-session",
-		"jwks_uri":                              appUrl + "/.well-known/jwks.json",
+		"authorization_endpoint":                utils.GetAbsoluteURL(appUrl, "/authorize"),
+		"token_endpoint":                        utils.GetAbsoluteURL(appUrl, "/api/oidc/token"),
+		"userinfo_endpoint":                     utils.GetAbsoluteURL(appUrl, "/api/oidc/userinfo"),
+		"end_session_endpoint":                  utils.GetAbsoluteURL(appUrl, "/api/oidc/end-session"),
+		"jwks_uri":                              utils.GetAbsoluteURL(appUrl, "/.well-known/jwks.json"),
 		"scopes_supported":                      []string{"openid", "profile", "email"},
 		"claims_supported":                      []string{"sub", "given_name", "family_name", "name", "email", "email_verified", "preferred_username", "picture"},
 		"response_types_supported":              []string{"code", "id_token"},
diff --git a/backend/internal/service/email_service.go b/backend/internal/service/email_service.go
index 2aa6cb6..1c5aa89 100644
--- a/backend/internal/service/email_service.go
+++ b/backend/internal/service/email_service.go
@@ -16,6 +16,7 @@ import (
 
 	"github.com/pocket-id/pocket-id/backend/internal/common"
 	"github.com/pocket-id/pocket-id/backend/internal/model"
+	"github.com/pocket-id/pocket-id/backend/internal/utils"
 	"github.com/pocket-id/pocket-id/backend/internal/utils/email"
 	"gorm.io/gorm"
 )
@@ -66,7 +67,7 @@ func (srv *EmailService) SendTestEmail(recipientUserId string) error {
 func SendEmail[V any](srv *EmailService, toEmail email.Address, template email.Template[V], tData *V) error {
 	data := &email.TemplateData[V]{
 		AppName: srv.appConfigService.DbConfig.AppName.Value,
-		LogoURL: common.EnvConfig.AppURL + "/api/application-configuration/logo",
+		LogoURL: utils.GetAbsoluteURL(common.EnvConfig.AppURL, "/api/application-configuration/logo"),
 		Data:    tData,
 	}
 
diff --git a/backend/internal/service/oidc_service.go b/backend/internal/service/oidc_service.go
index 96967cc..f9293cb 100644
--- a/backend/internal/service/oidc_service.go
+++ b/backend/internal/service/oidc_service.go
@@ -401,7 +401,7 @@ func (s *OidcService) GetUserClaimsForClient(userID string, clientID string) (ma
 		"family_name":        user.LastName,
 		"name":               user.FullName(),
 		"preferred_username": user.Username,
-		"picture":            fmt.Sprintf("%s/api/users/%s/profile-picture.png", common.EnvConfig.AppURL, user.ID),
+		"picture":            utils.GetAbsoluteURL(common.EnvConfig.AppURL, fmt.Sprintf("/api/users/%s/profile-picture.png", user.ID)),
 	}
 
 	if strings.Contains(scope, "profile") {
diff --git a/backend/internal/service/user_service.go b/backend/internal/service/user_service.go
index 2166f02..ecc562a 100644
--- a/backend/internal/service/user_service.go
+++ b/backend/internal/service/user_service.go
@@ -3,8 +3,6 @@ package service
 import (
 	"errors"
 	"fmt"
-	"github.com/google/uuid"
-	"github.com/pocket-id/pocket-id/backend/internal/utils/image"
 	"io"
 	"log"
 	"net/url"
@@ -12,6 +10,9 @@ import (
 	"strings"
 	"time"
 
+	"github.com/google/uuid"
+	profilepicture "github.com/pocket-id/pocket-id/backend/internal/utils/image"
+
 	"github.com/pocket-id/pocket-id/backend/internal/common"
 	"github.com/pocket-id/pocket-id/backend/internal/dto"
 	"github.com/pocket-id/pocket-id/backend/internal/model"
@@ -197,7 +198,7 @@ func (s *UserService) RequestOneTimeAccessEmail(emailAddress, redirectPath strin
 		return err
 	}
 
-	link := fmt.Sprintf("%s/login/%s", common.EnvConfig.AppURL, oneTimeAccessToken)
+	link := utils.GetAbsoluteURL(common.EnvConfig.AppURL, fmt.Sprintf("/login/%s", oneTimeAccessToken))
 
 	// Add redirect path to the link
 	if strings.HasPrefix(redirectPath, "/") {
diff --git a/backend/internal/utils/string_util.go b/backend/internal/utils/string_util.go
index 24c78c9..ed59935 100644
--- a/backend/internal/utils/string_util.go
+++ b/backend/internal/utils/string_util.go
@@ -40,6 +40,15 @@ func GetHostnameFromURL(rawURL string) string {
 	return parsedURL.Hostname()
 }
 
+// Returns an absolute path when provided with a URL (https://test.com) and a path "/.well-known/openid-configuration"
+func GetAbsoluteURL(baseURL string, path string) string {
+	url, err := url.JoinPath(baseURL, path)
+	if err != nil {
+		return ""
+	}
+	return url
+}
+
 // StringPointer creates a string pointer from a string value
 func StringPointer(s string) *string {
 	return &s