diff --git a/src/Mapster.Tests/WhenRegisteringAndMappingRace.cs b/src/Mapster.Tests/WhenRegisteringAndMappingRace.cs
index e6d796dc..f32250c6 100644
--- a/src/Mapster.Tests/WhenRegisteringAndMappingRace.cs
+++ b/src/Mapster.Tests/WhenRegisteringAndMappingRace.cs
@@ -1,8 +1,9 @@
-using System;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Shouldly;
+using System;
 using System.Collections.Generic;
+using System.Reflection;
 using System.Threading.Tasks;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-using Shouldly;
 
 namespace Mapster.Tests
 {
@@ -39,6 +40,12 @@ public void Race_Condition_Produces_Error()
 
             var simplePoco = new WhenAddingCustomMappings.SimplePoco {Id = Guid.NewGuid(), Name = "TestName"};
 
+            //first state (i = 0) Must be configured
+            TypeAdapterConfig<WhenAddingCustomMappings.SimplePoco, WeirdPoco>.NewConfig()
+                               .Map(dest => dest.IHaveADifferentId, src => src.Id)
+                               .Map(dest => dest.MyNamePropertyIsDifferent, src => src.Name)
+                               .Ignore(dest => dest.Children);
+
             var exception = Should.Throw<AggregateException>(() =>
             {
                 for (int i = 0; i < 100; i++)
@@ -66,6 +73,12 @@ public void Explicit_Mapping_Requirement_Throws_Before_Mapping_Attempted()
             TypeAdapterConfig.GlobalSettings.RequireExplicitMapping = true;
             TypeAdapterConfig.GlobalSettings.RequireDestinationMemberSource = true;
 
+            //first state (i = 0) Must be configured
+            TypeAdapterConfig<WhenAddingCustomMappings.SimplePoco, WeirdPoco>.NewConfig()
+                               .Map(dest => dest.IHaveADifferentId, src => src.Id)
+                               .Map(dest => dest.MyNamePropertyIsDifferent, src => src.Name)
+                               .Ignore(dest => dest.Children);
+
             var simplePoco = new WhenAddingCustomMappings.SimplePoco { Id = Guid.NewGuid(), Name = "TestName" };
 
             Should.Throw<AggregateException>(() =>
@@ -89,12 +102,87 @@ public void Explicit_Mapping_Requirement_Throws_Before_Mapping_Attempted()
             TypeAdapter.Adapt<WhenAddingCustomMappings.SimplePoco, WeirdPoco>(simplePoco);
         }
 
+        [TestMethod]
+        public void Race_Condition_Working()
+        {
+            TypeAdapterConfig.GlobalSettings.RequireExplicitMapping = true;
+            TypeAdapterConfig.GlobalSettings.RequireDestinationMemberSource = true;
+
+            var simplePoco = new WhenAddingCustomMappings.SimplePoco { Id = Guid.NewGuid(), Name = "TestName" };
 
+            //first state (i = 0) Must be configured
+            TypeAdapterConfigConcurrency<WhenAddingCustomMappings.SimplePoco, WeirdPoco>
+                .NewConfig(cfg =>
+                {
+                    cfg
+                        .Map(dest => dest.IHaveADifferentId, src => src.Id)
+                        .Map(dest => dest.IHaveADifferentId, src => src.Id)
+                        .Map(dest => dest.MyNamePropertyIsDifferent, src => src.Name)
+                        .Ignore(dest => dest.Children);
+                });
+
+            for (int i = 0; i < 1000; i++)
+            {
+                Parallel.Invoke(
+                    () =>
+                    {
+                        TypeAdapterConfigConcurrency<WhenAddingCustomMappings.SimplePoco, WeirdPoco>
+                            .NewConfig(cfg =>
+                            {
+                                cfg
+                                    .Map(dest => dest.IHaveADifferentId, src => src.Id)
+                                    .Map(dest => dest.IHaveADifferentId, src => src.Id)
+                                    .Map(dest => dest.MyNamePropertyIsDifferent, src => src.Name)
+                                    .Ignore(dest => dest.Children);
+                            });
+                    },
+                    () => { TypeAdapter.Adapt<WeirdPoco>(simplePoco); }
+                    );
+            }
+
+        }
+
+        [TestMethod]
+        public void Scan_Race_Condition_Working()
+        {
+            TypeAdapterConfig.GlobalSettings.RequireExplicitMapping = true;
+            TypeAdapterConfig.GlobalSettings.RequireDestinationMemberSource = true;
+
+            var simplePoco = new WhenAddingCustomMappings.SimplePoco { Id = Guid.NewGuid(), Name = "TestName" };
+
+            //first state (i = 0) Must be configured
+            TypeAdapterConfig.GlobalSettings.Scan(Assembly.GetExecutingAssembly());
+
+
+            for (int i = 0; i < 1000; i++)
+            {
+                Parallel.Invoke(
+                    () =>
+                    {
+                        TypeAdapterConfig.GlobalSettings.ScanConcurrency(Assembly.GetExecutingAssembly());
+                    },
+                    () => { TypeAdapter.Adapt<WeirdPoco>(simplePoco); }
+                    );
+            }
+
+        }
     }
 
 
     #region TestClasses
 
+    public class RegData : IRegister
+    {
+        public void Register(TypeAdapterConfig config)
+        {
+            config.NewConfig<WhenAddingCustomMappings.SimplePoco, WeirdPoco>()
+            .Map(dest => dest.IHaveADifferentId, src => src.Id)
+            .Map(dest => dest.MyNamePropertyIsDifferent, src => src.Name)
+            .Ignore(dest => dest.Children);
+
+        }
+    }
+
     public class SimplePoco
     {
         public Guid Id { get; set; }
diff --git a/src/Mapster.Tests/WhenScanningForRegisters.cs b/src/Mapster.Tests/WhenScanningForRegisters.cs
index 20b287b6..c86e1298 100644
--- a/src/Mapster.Tests/WhenScanningForRegisters.cs
+++ b/src/Mapster.Tests/WhenScanningForRegisters.cs
@@ -16,7 +16,7 @@ public void Registers_Are_Found()
         {
             var config = new TypeAdapterConfig();
             IList<IRegister> registers = config.Scan(Assembly.GetExecutingAssembly());
-            registers.Count.ShouldBe(2);
+            registers.Count.ShouldBe(3);
 
             var typeTuples = config.RuleMap.Keys.ToList();
 
diff --git a/src/Mapster/TypeAdapterConfig.cs b/src/Mapster/TypeAdapterConfig.cs
index 1e6abade..f865c3d8 100644
--- a/src/Mapster/TypeAdapterConfig.cs
+++ b/src/Mapster/TypeAdapterConfig.cs
@@ -1,18 +1,26 @@
-using System;
+using Mapster.Adapters;
+using Mapster.Models;
+using Mapster.Utils;
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Runtime.CompilerServices;
-using Mapster.Adapters;
-using Mapster.Models;
-using Mapster.Utils;
+using System.Threading;
 
 namespace Mapster
 {
     public class TypeAdapterConfig
     {
+        #region ConcurrencyMod
+
+        [AdaptIgnore]
+        internal AutoResetEvent ConfigureSync { get; set; }
+
+        #endregion ConcurrencyMod
+
         public static List<TypeAdapterRule> RulesTemplate { get; } = CreateRuleTemplate();
         public static TypeAdapterConfig GlobalSettings { get; } = new TypeAdapterConfig();
 
@@ -95,6 +103,8 @@ private static List<TypeAdapterRule> CreateRuleTemplate()
 
         public TypeAdapterConfig()
         {
+            ConfigureSync = new(true);
+           
             Rules = RulesTemplate.ToList();
             var settings = new TypeAdapterSettings();
             Default = new TypeAdapterSetter(settings, this);
@@ -322,10 +332,19 @@ public Func<TSource, TDestination> GetMapFunction<TSource, TDestination>()
         }
         internal Delegate GetMapFunction(Type sourceType, Type destinationType)
         {
-            var key = new TypeTuple(sourceType, destinationType);
-            if (!_mapDict.TryGetValue(key, out var del))
-                del = AddToHash(_mapDict, key, tuple => Compiler(CreateMapExpression(tuple, MapType.Map)));
-            return del;
+            ConfigureSync.WaitOne();
+
+            try
+            {
+                var key = new TypeTuple(sourceType, destinationType);
+                if (!_mapDict.TryGetValue(key, out var del))
+                    del = AddToHash(_mapDict, key, tuple => Compiler(CreateMapExpression(tuple, MapType.Map)));
+                return del;
+            }
+            finally
+            {
+                ConfigureSync.Set();
+            }
         }
 
         private readonly ConcurrentDictionary<TypeTuple, Delegate> _mapToTargetDict = new ConcurrentDictionary<TypeTuple, Delegate>();
@@ -335,10 +354,20 @@ public Func<TSource, TDestination, TDestination> GetMapToTargetFunction<TSource,
         }
         internal Delegate GetMapToTargetFunction(Type sourceType, Type destinationType)
         {
-            var key = new TypeTuple(sourceType, destinationType);
-            if (!_mapToTargetDict.TryGetValue(key, out var del))
-                del = AddToHash(_mapToTargetDict, key, tuple => Compiler(CreateMapExpression(tuple, MapType.MapToTarget)));
-            return del;
+            ConfigureSync.WaitOne();
+
+            try
+            {
+                var key = new TypeTuple(sourceType, destinationType);
+                if (!_mapToTargetDict.TryGetValue(key, out var del))
+                    del = AddToHash(_mapToTargetDict, key, tuple => Compiler(CreateMapExpression(tuple, MapType.MapToTarget)));
+                return del;
+            }
+            finally
+            {
+                ConfigureSync.Set();
+            }
+            
         }
 
         private readonly ConcurrentDictionary<TypeTuple, MethodCallExpression> _projectionDict = new ConcurrentDictionary<TypeTuple, MethodCallExpression>();
@@ -350,19 +379,37 @@ internal Expression<Func<TSource, TDestination>> GetProjectionExpression<TSource
         }
         internal MethodCallExpression GetProjectionCallExpression(Type sourceType, Type destinationType)
         {
-            var key = new TypeTuple(sourceType, destinationType);
-            if (!_projectionDict.TryGetValue(key, out var del))
-                del = AddToHash(_projectionDict, key, CreateProjectionCallExpression);
-            return del;
+            ConfigureSync.WaitOne();
+
+            try
+            {
+                var key = new TypeTuple(sourceType, destinationType);
+                if (!_projectionDict.TryGetValue(key, out var del))
+                    del = AddToHash(_projectionDict, key, CreateProjectionCallExpression);
+                return del;
+            }
+            finally
+            {
+                ConfigureSync.Set();
+            }
         }
 
         private readonly ConcurrentDictionary<TypeTuple, Delegate> _dynamicMapDict = new ConcurrentDictionary<TypeTuple, Delegate>();
         public Func<object, TDestination> GetDynamicMapFunction<TDestination>(Type sourceType)
         {
-            var key = new TypeTuple(sourceType, typeof(TDestination));
-            if (!_dynamicMapDict.TryGetValue(key, out var del))
-                del = AddToHash(_dynamicMapDict, key, tuple => Compiler(CreateDynamicMapExpression(tuple)));
-            return (Func<object, TDestination>)del;
+            ConfigureSync.WaitOne();
+
+            try
+            {
+                var key = new TypeTuple(sourceType, typeof(TDestination));
+                if (!_dynamicMapDict.TryGetValue(key, out var del))
+                    del = AddToHash(_dynamicMapDict, key, tuple => Compiler(CreateDynamicMapExpression(tuple)));
+                return (Func<object, TDestination>)del;
+            }
+            finally
+            {
+                ConfigureSync.Set();
+            }
         }
 
         private Expression CreateSelfExpression()
@@ -403,6 +450,7 @@ public LambdaExpression CreateMapExpression(TypeTuple tuple, MapType mapType)
             }
             finally
             {
+               
                 if (fork != null)
                     context.Configs.Pop();
                 context.Running.Remove(tuple);
@@ -738,12 +786,25 @@ public IList<IRegister> Scan(params Assembly[] assemblies)
             return registers;
         }
 
+        public IList<IRegister> ScanConcurrency(params Assembly[] assemblies)
+        {
+            ConfigureSync.WaitOne();
+           
+            try
+            {
+                return Scan(assemblies);
+            }
+            finally
+            {
+                ConfigureSync.Set();
+            }
+        }
 
-		/// <summary>
-		/// Applies type mappings.
-		/// </summary>
-		/// <param name="registers">collection of IRegister interface to apply mapping.</param>
-		public void Apply(IEnumerable<Lazy<IRegister>> registers)
+        /// <summary>
+        /// Applies type mappings.
+        /// </summary>
+        /// <param name="registers">collection of IRegister interface to apply mapping.</param>
+        public void Apply(IEnumerable<Lazy<IRegister>> registers)
         {
             Apply(registers.Select(register => register.Value));
         }
@@ -882,4 +943,23 @@ public static void Clear()
             TypeAdapterConfig.GlobalSettings.Remove(typeof(TSource), typeof(TDestination));
         }
     }
+
+    public static class TypeAdapterConfigConcurrency<TSource, TDestination>
+    {
+        public static void NewConfig(Action<TypeAdapterSetter<TSource, TDestination>> cfg)
+        {
+            var config = TypeAdapterConfig.GlobalSettings;
+
+            config.ConfigureSync.WaitOne();
+
+            try
+            {
+                cfg.Invoke(TypeAdapterConfig<TSource, TDestination>.NewConfig());
+            }
+            finally
+            {
+                config.ConfigureSync.Set();
+            }
+        }
+    }
 }
\ No newline at end of file