diff --git a/src/Umbraco.Web/WebApi/UmbracoApiController.cs b/src/Umbraco.Web/WebApi/UmbracoApiController.cs
index 8a2e54ca02..60b225ae96 100644
--- a/src/Umbraco.Web/WebApi/UmbracoApiController.cs
+++ b/src/Umbraco.Web/WebApi/UmbracoApiController.cs
@@ -1,8 +1,10 @@
-using Umbraco.Core;
+using System;
+using Umbraco.Core;
 using Umbraco.Core.Cache;
 using Umbraco.Core.Composing;
 using Umbraco.Core.Configuration;
 using Umbraco.Core.Logging;
+using Umbraco.Core.Mapping;
 using Umbraco.Core.Persistence;
 using Umbraco.Core.Services;
 
@@ -17,8 +19,14 @@ namespace Umbraco.Web.WebApi
         {
         }
 
+        [Obsolete("This constructor uses the service locator to fetch the UmbracoMapper from Current.Mapper, which is not good for testability. Inject the UmbracoMapper using full constructor injection instead.")]
         protected UmbracoApiController(IGlobalSettings globalSettings, IUmbracoContextAccessor umbracoContextAccessor, ISqlContext sqlContext, ServiceContext services, AppCaches appCaches, IProfilingLogger logger, IRuntimeState runtimeState, UmbracoHelper umbracoHelper)
-            : base(globalSettings, umbracoContextAccessor, sqlContext, services, appCaches, logger, runtimeState, umbracoHelper)
+            : base(globalSettings, umbracoContextAccessor, sqlContext, services, appCaches, logger, runtimeState, umbracoHelper, Current.Mapper)
+        {
+        }
+
+        protected UmbracoApiController(IGlobalSettings globalSettings, IUmbracoContextAccessor umbracoContextAccessor, ISqlContext sqlContext, ServiceContext services, AppCaches appCaches, IProfilingLogger logger, IRuntimeState runtimeState, UmbracoHelper umbracoHelper, UmbracoMapper umbracoMapper)
+            : base(globalSettings, umbracoContextAccessor, sqlContext, services, appCaches, logger, runtimeState, umbracoHelper, umbracoMapper)
         {
         }
     }
diff --git a/src/Umbraco.Web/WebApi/UmbracoApiControllerBase.cs b/src/Umbraco.Web/WebApi/UmbracoApiControllerBase.cs
index 89a630fb5d..874c1c8a4f 100644
--- a/src/Umbraco.Web/WebApi/UmbracoApiControllerBase.cs
+++ b/src/Umbraco.Web/WebApi/UmbracoApiControllerBase.cs
@@ -40,14 +40,15 @@ namespace Umbraco.Web.WebApi
                 Current.Factory.GetInstance<AppCaches>(),
                 Current.Factory.GetInstance<IProfilingLogger>(),
                 Current.Factory.GetInstance<IRuntimeState>(),
-                Current.Factory.GetInstance<UmbracoHelper>()
+                Current.Factory.GetInstance<UmbracoHelper>(),
+                Current.Factory.GetInstance<UmbracoMapper>()
             )
         { }
 
         /// <summary>
         /// Initializes a new instance of the <see cref="UmbracoApiControllerBase"/> class with all its dependencies.
         /// </summary>
-        protected UmbracoApiControllerBase(IGlobalSettings globalSettings, IUmbracoContextAccessor umbracoContextAccessor, ISqlContext sqlContext, ServiceContext services, AppCaches appCaches, IProfilingLogger logger, IRuntimeState runtimeState, UmbracoHelper umbracoHelper)
+        protected UmbracoApiControllerBase(IGlobalSettings globalSettings, IUmbracoContextAccessor umbracoContextAccessor, ISqlContext sqlContext, ServiceContext services, AppCaches appCaches, IProfilingLogger logger, IRuntimeState runtimeState, UmbracoHelper umbracoHelper, UmbracoMapper umbracoMapper)
         {
             UmbracoContextAccessor = umbracoContextAccessor;
             GlobalSettings = globalSettings;
@@ -57,9 +58,7 @@ namespace Umbraco.Web.WebApi
             Logger = logger;
             RuntimeState = runtimeState;
             Umbraco = umbracoHelper;
-
-            // fixme - can we break all ctors?
-            Mapper = Current.Mapper;
+            Mapper = umbracoMapper;
         }
 
         /// <summary>