diff --git a/src/libraries/System.ObjectModel/tests/KeyedCollection/Serialization.cs b/src/libraries/System.ObjectModel/tests/KeyedCollection/Serialization.cs
index a43c4f08d496af..1c14406006779d 100644
--- a/src/libraries/System.ObjectModel/tests/KeyedCollection/Serialization.cs
+++ b/src/libraries/System.ObjectModel/tests/KeyedCollection/Serialization.cs
@@ -16,7 +16,7 @@ public static IEnumerable<object[]> SerializeDeserialize_Roundtrips_MemberData()
             yield return new object[] { new TestCollection() { "hello", "world" } };
         }
 
-        [Theory]
+        [ConditionalTheory(typeof(PlatformDetection), nameof(PlatformDetection.IsBinaryFormatterSupported))]
         [MemberData(nameof(SerializeDeserialize_Roundtrips_MemberData))]
         public void SerializeDeserialize_Roundtrips(TestCollection c)
         {
diff --git a/src/libraries/System.ObjectModel/tests/ObservableCollection/ObservableCollection_Serialization.cs b/src/libraries/System.ObjectModel/tests/ObservableCollection/ObservableCollection_Serialization.cs
index 1d2875576e4176..65d5694a93a8f3 100644
--- a/src/libraries/System.ObjectModel/tests/ObservableCollection/ObservableCollection_Serialization.cs
+++ b/src/libraries/System.ObjectModel/tests/ObservableCollection/ObservableCollection_Serialization.cs
@@ -17,7 +17,7 @@ public static IEnumerable<object[]> SerializeDeserialize_Roundtrips_MemberData()
             yield return new object[] { new ObservableCollection<int>() { 1, 5, 3, 4, 2 } };
         }
 
-        [Theory]
+        [ConditionalTheory(typeof(PlatformDetection), nameof(PlatformDetection.IsBinaryFormatterSupported))]
         [MemberData(nameof(SerializeDeserialize_Roundtrips_MemberData))]
         public void SerializeDeserialize_Roundtrips(ObservableCollection<int> c)
         {
diff --git a/src/libraries/System.ObjectModel/tests/ReadOnlyDictionary/ReadOnlyDictionary_SerializationTests.cs b/src/libraries/System.ObjectModel/tests/ReadOnlyDictionary/ReadOnlyDictionary_SerializationTests.cs
index af7aec630bbd26..d0bb38d21623eb 100644
--- a/src/libraries/System.ObjectModel/tests/ReadOnlyDictionary/ReadOnlyDictionary_SerializationTests.cs
+++ b/src/libraries/System.ObjectModel/tests/ReadOnlyDictionary/ReadOnlyDictionary_SerializationTests.cs
@@ -16,7 +16,7 @@ public static IEnumerable<object[]> SerializeDeserialize_Roundtrips_MemberData()
             yield return new object[] { new ReadOnlyDictionary<string, string>(new Dictionary<string, string>() { { "a", "b" }, { "c", "d" } }) };
         }
 
-        [Theory]
+        [ConditionalTheory(typeof(PlatformDetection), nameof(PlatformDetection.IsBinaryFormatterSupported))]
         [MemberData(nameof(SerializeDeserialize_Roundtrips_MemberData))]
         public void SerializeDeserialize_Roundtrips(ReadOnlyDictionary<string, string> d)
         {
diff --git a/src/libraries/System.ObjectModel/tests/ReadOnlyObservableCollection/ReadOnlyObservableCollection_SerializationTests.cs b/src/libraries/System.ObjectModel/tests/ReadOnlyObservableCollection/ReadOnlyObservableCollection_SerializationTests.cs
index b2e102dd64b2a3..ed818b6a619818 100644
--- a/src/libraries/System.ObjectModel/tests/ReadOnlyObservableCollection/ReadOnlyObservableCollection_SerializationTests.cs
+++ b/src/libraries/System.ObjectModel/tests/ReadOnlyObservableCollection/ReadOnlyObservableCollection_SerializationTests.cs
@@ -17,7 +17,7 @@ public static IEnumerable<object[]> SerializeDeserialize_Roundtrips_MemberData()
             yield return new object[] { new ReadOnlyObservableCollection<int>(new ObservableCollection<int>() { 1, 2, 3 }) };
         }
 
-        [Theory]
+        [ConditionalTheory(typeof(PlatformDetection), nameof(PlatformDetection.IsBinaryFormatterSupported))]
         [MemberData(nameof(SerializeDeserialize_Roundtrips_MemberData))]
         public void SerializeDeserialize_Roundtrips(ReadOnlyObservableCollection<int> c)
         {
diff --git a/src/libraries/tests.proj b/src/libraries/tests.proj
index eb67053b5b88bd..b35563aebd6426 100644
--- a/src/libraries/tests.proj
+++ b/src/libraries/tests.proj
@@ -33,7 +33,6 @@
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Linq.Parallel\tests\System.Linq.Parallel.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.Http\tests\FunctionalTests\System.Net.Http.Functional.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.WebSockets.Client\tests\System.Net.WebSockets.Client.Tests.csproj" />
-    <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.ObjectModel\tests\System.ObjectModel.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Private.Uri\tests\FunctionalTests\System.Private.Uri.Functional.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.ValueTuple\tests\System.ValueTuple.Tests.csproj" />
   </ItemGroup>