diff --git a/src/tests/JIT/Regression/CLR-x86-JIT/V1.2-M01/b08046cs/SyncGCHole.cs b/src/tests/JIT/Regression/CLR-x86-JIT/V1.2-M01/b08046cs/SyncGCHole.cs
index b98adbf96396f2..3978e44cfe8bf8 100644
--- a/src/tests/JIT/Regression/CLR-x86-JIT/V1.2-M01/b08046cs/SyncGCHole.cs
+++ b/src/tests/JIT/Regression/CLR-x86-JIT/V1.2-M01/b08046cs/SyncGCHole.cs
@@ -21,6 +21,7 @@ namespace b08046cs;
 using System;
 using System.Runtime.CompilerServices;
 using System.Threading;
+using TestLibrary;
 using Xunit;
 
 class ExternalClass
@@ -42,7 +43,7 @@ public class ExternalException : Exception
     public static int Ignored { get; set; }
 
     [OuterLoop]
-    [Fact]
+    [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsMultithreadingSupported))]
     public static int TestEntryPoint()
     {
         ExitCode = 100;
diff --git a/src/tests/JIT/Regression/CLR-x86-JIT/v2.1/b72218/b72218.cs b/src/tests/JIT/Regression/CLR-x86-JIT/v2.1/b72218/b72218.cs
index fbcb25f378b1a0..f8c12f6138f905 100644
--- a/src/tests/JIT/Regression/CLR-x86-JIT/v2.1/b72218/b72218.cs
+++ b/src/tests/JIT/Regression/CLR-x86-JIT/v2.1/b72218/b72218.cs
@@ -7,6 +7,7 @@ namespace b72218;
 
 using System;
 using System.Threading;
+using TestLibrary;
 using Xunit;
 
 public class My
@@ -19,7 +20,7 @@ static void Worker()
     }
 
     [OuterLoop]
-    [Fact]
+    [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsMultithreadingSupported))]
     public static void TestEntryPoint()
     {