diff --git a/mrbgems/mruby-dir/mrbgem.rake b/mrbgems/mruby-dir/mrbgem.rake
index 71ed21cbd..905d28697 100644
--- a/mrbgems/mruby-dir/mrbgem.rake
+++ b/mrbgems/mruby-dir/mrbgem.rake
@@ -6,12 +6,18 @@ MRuby::Gem::Specification.new('mruby-dir') do |spec|
   # HAL gems must be explicitly specified in build config (recommended) or via auto-selection below
   spec.build.gems.one? { |g| g.name =~ /^hal-.*-dir$/ } or begin
     # No HAL found - determine appropriate error message or auto-load
+    # MinGW provides POSIX compatibility, so use hal-posix-dir
+    # Detect MinGW by checking host_target or compiler command
+    is_mingw = (spec.build.kind_of?(MRuby::CrossBuild) &&
+                spec.build.host_target =~ /mingw/) ||
+               spec.cc.command.to_s =~ /mingw/
+
     suggested_hal = if ENV['MRUBY_DIR_HAL']
       ENV['MRUBY_DIR_HAL']
+    elsif RUBY_PLATFORM =~ /linux|darwin|bsd/ || is_mingw
+      'hal-posix-dir'
     elsif spec.for_windows?
       'hal-win-dir'
-    elsif RUBY_PLATFORM =~ /linux|darwin|bsd/
-      'hal-posix-dir'
     else
       nil
     end
diff --git a/mrbgems/mruby-io/mrbgem.rake b/mrbgems/mruby-io/mrbgem.rake
index 6663666df..8bab028ca 100644
--- a/mrbgems/mruby-io/mrbgem.rake
+++ b/mrbgems/mruby-io/mrbgem.rake
@@ -10,10 +10,16 @@ MRuby::Gem::Specification.new('mruby-io') do |spec|
   # HAL gems must be explicitly specified in build config (recommended) or via auto-selection below
   spec.build.gems.one? { |g| g.name =~ /^hal-.*-io$/ } or begin
     # No HAL found - determine appropriate error message or auto-load
-    suggested_hal = if spec.for_windows?
-      'hal-win-io'
-    elsif RUBY_PLATFORM =~ /linux|darwin|bsd/
+    # MinGW provides POSIX compatibility, so use hal-posix-io
+    # Detect MinGW by checking host_target or compiler command
+    is_mingw = (spec.build.kind_of?(MRuby::CrossBuild) &&
+                spec.build.host_target =~ /mingw/) ||
+               spec.cc.command.to_s =~ /mingw/
+
+    suggested_hal = if RUBY_PLATFORM =~ /linux|darwin|bsd/ || is_mingw
       'hal-posix-io'
+    elsif spec.for_windows?
+      'hal-win-io'
     else
       nil
     end