diff --git a/src/BizHawk.Tests/Client.Common/lua/LuaTests.cs b/src/BizHawk.Tests/Client.Common/lua/LuaTests.cs
index 93b70b933a..9f42381f8c 100644
--- a/src/BizHawk.Tests/Client.Common/lua/LuaTests.cs
+++ b/src/BizHawk.Tests/Client.Common/lua/LuaTests.cs
@@ -10,6 +10,7 @@ using Microsoft.VisualStudio.TestTools.UnitTesting;
 namespace BizHawk.Tests.Client.Common.Lua
 {
 #if !SKIP_PLATFORM_TESTS
+	[DoNotParallelize]
 	[TestClass]
 #endif
 	public class LuaTests
diff --git a/src/BizHawk.Tests/Common/checksums/CRC32Tests.cs b/src/BizHawk.Tests/Common/checksums/CRC32Tests.cs
index 734c3d7912..578281ebe0 100644
--- a/src/BizHawk.Tests/Common/checksums/CRC32Tests.cs
+++ b/src/BizHawk.Tests/Common/checksums/CRC32Tests.cs
@@ -4,6 +4,7 @@ using Microsoft.VisualStudio.TestTools.UnitTesting;
 
 namespace BizHawk.Tests.Common.checksums
 {
+	[DoNotParallelize] // I only noticed problems w/ SHA1, but better safe than sorry --yoshi
 	[TestClass]
 	public sealed class CRC32Tests
 	{
diff --git a/src/BizHawk.Tests/Common/checksums/SHA1Tests.cs b/src/BizHawk.Tests/Common/checksums/SHA1Tests.cs
index 55dcd8143b..4cabee087f 100644
--- a/src/BizHawk.Tests/Common/checksums/SHA1Tests.cs
+++ b/src/BizHawk.Tests/Common/checksums/SHA1Tests.cs
@@ -7,6 +7,7 @@ using Microsoft.VisualStudio.TestTools.UnitTesting;
 
 namespace BizHawk.Tests.Common.checksums
 {
+	[DoNotParallelize]
 	[TestClass]
 	public sealed class SHA1Tests
 	{