diff --git a/Kontent.Ai.Management.Tests/ManagementClientTests/SpaceTests.cs b/Kontent.Ai.Management.Tests/ManagementClientTests/SpaceTests.cs
index 05824511..536961ee 100644
--- a/Kontent.Ai.Management.Tests/ManagementClientTests/SpaceTests.cs
+++ b/Kontent.Ai.Management.Tests/ManagementClientTests/SpaceTests.cs
@@ -1,3 +1,4 @@
+using FluentAssertions;
 using Kontent.Ai.Management.Models.Shared;
 using Kontent.Ai.Management.Models.Spaces;
 using Kontent.Ai.Management.Models.Spaces.Patch;
@@ -35,6 +36,14 @@ public async void CreateSpace_CreatesSpace()
             .Validate();
     }
 
+    [Fact]
+    public async void CreateSpace_ModelIsNull_Throws()
+    {
+        var client = _scenario.CreateManagementClient();
+
+        await client.Invoking(x => x.CreateSpaceAsync(null)).Should().ThrowAsync<ArgumentNullException>();
+    }
+
     [Fact]
     public async void ListSpaces_ListsSpaces()
     {
@@ -79,6 +88,14 @@ public async void GetSpace_ByCodename_GetsSpace()
             .Validate();
     }
 
+    [Fact]
+    public async void GetSpace_IdentifierIsNull_Throws()
+    {
+        var client = _scenario.CreateManagementClient();
+
+        await client.Invoking(x => x.GetSpaceAsync(null)).Should().ThrowAsync<ArgumentNullException>();
+    }
+
     [Fact]
     public async void ModifySpace_Replace_ModifiesSpace()
     {
@@ -101,6 +118,27 @@ public async void ModifySpace_Replace_ModifiesSpace()
             .Validate();
     }
 
+    [Fact]
+    public async void ModifySpace_IdentifierIsNull_Throws()
+    {
+        var client = _scenario.CreateManagementClient();
+        var changes = new SpaceOperationReplaceModel[]
+        {
+            new() { PropertyName = PropertyName.Name, Value = "New space name" }
+        };
+
+        await client.Invoking(x => x.ModifySpaceAsync(null, changes)).Should().ThrowAsync<ArgumentNullException>();
+    }
+
+    [Fact]
+    public async void ModifySpace_ChangesAreNull_Throws()
+    {
+        var client = _scenario.CreateManagementClient();
+        var identifier = Reference.ById(Guid.NewGuid());
+
+        await client.Invoking(x => x.ModifySpaceAsync(identifier, null)).Should().ThrowAsync<ArgumentNullException>();
+    }
+
     [Fact]
     public async void DeleteSpace_ById_DeletesSpace()
     {
@@ -129,5 +167,13 @@ public async void DeleteSpace_ByCodename_DeletesSpace()
             .HttpMethod(HttpMethod.Delete)
             .Validate();
     }
+
+    [Fact]
+    public async void DeleteSpace_IdentifierIsNull_Throws()
+    {
+        var client = _scenario.CreateManagementClient();
+
+        await client.Invoking(x => x.DeleteSpaceAsync(null)).Should().ThrowAsync<ArgumentNullException>();
+    }
 }
     
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