diff --git a/bootstraptest/pending.rb b/bootstraptest/pending.rb
index 744c0adac1..fa4e04c6da 100644
--- a/bootstraptest/pending.rb
+++ b/bootstraptest/pending.rb
@@ -37,3 +37,11 @@ assert_normal_exit %q{
   r.instance_eval { initialize r, r }
   r.inspect
 }
+
+# This test randomly fails on AppVeyor msys2 with:
+# test_thread.rb: A non-blocking socket operation could not be completed immediately. - read would block
+assert_finish 3, %{
+  th = Thread.new {sleep 0.2}
+  th.join(0.1)
+  th.join
+}
diff --git a/bootstraptest/test_thread.rb b/bootstraptest/test_thread.rb
index d16295de8b..2b549b9ed9 100644
--- a/bootstraptest/test_thread.rb
+++ b/bootstraptest/test_thread.rb
@@ -248,12 +248,6 @@ assert_equal 'ok', %{
   $result
 }
 
-assert_finish 3, %{
-  th = Thread.new {sleep 0.2}
-  th.join(0.1)
-  th.join
-}
-
 assert_finish 3, %{
   require 'timeout'
   th = Thread.new {sleep 0.2}