diff --git a/.github/workflows/testing.yml b/.github/workflows/testing.yml
index 13471985..279ebc48 100644
--- a/.github/workflows/testing.yml
+++ b/.github/workflows/testing.yml
@@ -16,6 +16,8 @@ jobs:
         include:
           - os: ubuntu-20.04
             ruby: '3.1'
+          - os: macos-13
+            ruby: '3.0'
         exclude:
           # There's something wrong with this setup in GHA such that
           # it gets weird linking errors, however I'm unable to reproduce
diff --git a/lib/mkmf-rice.rb b/lib/mkmf-rice.rb
index 75ebcf30..ab9ead10 100644
--- a/lib/mkmf-rice.rb
+++ b/lib/mkmf-rice.rb
@@ -1,7 +1,7 @@
 require 'mkmf'
 
-IS_MSWIN = RbConfig::CONFIG['host_os'].match?(/mswin/)
-IS_MINGW = RbConfig::CONFIG['host_os'].match?(/mingw/)
+IS_MSWIN = /mswin/ =~ RUBY_PLATFORM
+IS_MINGW = /mingw/ =~ RUBY_PLATFORM
 IS_DARWIN = RbConfig::CONFIG['host_os'].match?(/darwin/)
 
 # The cpp_command is not overwritten in the experimental mkmf C++ support.
@@ -38,10 +38,6 @@ def cpp_command(outfile, opt="")
   raise("Could not find rice/rice.hpp header")
 end
 
-if IS_DARWIN
-  have_library('c++')
-elsif !IS_MSWIN
-  if !have_library('stdc++fs')
-    have_library('stdc++')
-  end
-end
\ No newline at end of file
+if !IS_DARWIN && !IS_MSWIN && !have_library('stdc++fs')
+  have_library('stdc++')
+end