diff --git a/src/OpenIddict.Client/OpenIddictClientHandlers.cs b/src/OpenIddict.Client/OpenIddictClientHandlers.cs
index 169aba2d..b692b351 100644
--- a/src/OpenIddict.Client/OpenIddictClientHandlers.cs
+++ b/src/OpenIddict.Client/OpenIddictClientHandlers.cs
@@ -2252,7 +2252,8 @@ public static partial class OpenIddictClientHandlers
                 string type => type
             };
 
-            if (context.Scopes.Count > 0)
+            if (context.Scopes.Count > 0 &&
+                context.TokenRequest.GrantType is not (GrantTypes.AuthorizationCode or GrantTypes.DeviceCode))
             {
                 // Note: the final OAuth 2.0 specification requires using a space as the scope separator.
                 // Clients that need to deal with older or non-compliant implementations can register
diff --git a/src/OpenIddict.Client/OpenIddictClientService.cs b/src/OpenIddict.Client/OpenIddictClientService.cs
index 6cded38e..6deb99ed 100644
--- a/src/OpenIddict.Client/OpenIddictClientService.cs
+++ b/src/OpenIddict.Client/OpenIddictClientService.cs
@@ -734,6 +734,11 @@ public sealed class OpenIddictClientService
                             is Dictionary<string, OpenIddictParameter> parameters ? new(parameters) : new(),
                     };
 
+                    if (request.Scopes is { Count: > 0 })
+                    {
+                        context.Scopes.UnionWith(request.Scopes);
+                    }
+
                     if (request.Properties is { Count: > 0 })
                     {
                         foreach (var property in request.Properties)