diff --git a/src/Umbraco.Core/Persistence/Repositories/MemberGroupRepository.cs b/src/Umbraco.Core/Persistence/Repositories/MemberGroupRepository.cs
index 404c32640a15..8b5dbb435e71 100644
--- a/src/Umbraco.Core/Persistence/Repositories/MemberGroupRepository.cs
+++ b/src/Umbraco.Core/Persistence/Repositories/MemberGroupRepository.cs
@@ -284,7 +284,7 @@ public void AssignRolesInternal(int[] memberIds, string[] roleNames)
                 var nonAssignedRoles = roleNames.Except(assignedRoles, StringComparer.CurrentCultureIgnoreCase);
                 foreach (var toAssign in nonAssignedRoles)
                 {
-                    var groupId = rolesForNames.First(x => x.Text == toAssign).NodeId;
+                    var groupId = rolesForNames.First(x => x.Text.InvariantEquals(toAssign)).NodeId;
                     Database.Insert(new Member2MemberGroupDto { Member = mId, MemberGroup = groupId });
                 }
             }
diff --git a/src/Umbraco.Tests/Services/MemberServiceTests.cs b/src/Umbraco.Tests/Services/MemberServiceTests.cs
index 4ba3866c646d..3ee5a4804ee4 100644
--- a/src/Umbraco.Tests/Services/MemberServiceTests.cs
+++ b/src/Umbraco.Tests/Services/MemberServiceTests.cs
@@ -288,6 +288,29 @@ public void Associate_Members_To_Roles_With_Member_Id()
             Assert.AreEqual(2, membersInRole.Count());
         }
 
+        [Test]
+        public void Associate_Members_To_Roles_With_Member_Id_Casing()
+        {
+            ServiceContext.MemberService.AddRole("MyTestRole1");
+
+            IMemberType memberType = MockedContentTypes.CreateSimpleMemberType();
+            ServiceContext.MemberTypeService.Save(memberType);
+            var member1 = MockedMember.CreateSimpleMember(memberType, "test1", "test1@test.com", "pass", "test1");
+            ServiceContext.MemberService.Save(member1);
+            var member2 = MockedMember.CreateSimpleMember(memberType, "test2", "test2@test.com", "pass", "test2");
+            ServiceContext.MemberService.Save(member2);
+
+            // temp make sure they exist
+            Assert.IsNotNull(ServiceContext.MemberService.GetById(member1.Id));
+            Assert.IsNotNull(ServiceContext.MemberService.GetById(member2.Id));
+
+            ServiceContext.MemberService.AssignRoles(new[] { member1.Id, member2.Id }, new[] { "mytestrole1" });
+
+            var membersInRole = ServiceContext.MemberService.GetMembersInRole("MyTestRole1");
+
+            Assert.AreEqual(2, membersInRole.Count());
+        }
+
         [Test]
         public void Associate_Members_To_Roles_With_Member_Username()
         {
@@ -1179,4 +1202,4 @@ public void Ensure_Content_Xml_Created()
         }
 
     }
-}
\ No newline at end of file
+}