diff --git a/ext/yajl/extconf.rb b/ext/yajl/extconf.rb
index 2c38204b..f689e303 100644
--- a/ext/yajl/extconf.rb
+++ b/ext/yajl/extconf.rb
@@ -1,7 +1,11 @@
 require 'mkmf'
 require 'rbconfig'
 
-$CFLAGS << ' -Wall -funroll-loops'
-$CFLAGS << ' -Werror-implicit-function-declaration -Wextra -O0 -ggdb3' if ENV['DEBUG']
+if RbConfig::CONFIG['host_os'] =~ /win(32|64)/
+  $CFLAGS << ' /Od /Zi' if ENV['DEBUG']
+else
+  $CFLAGS << ' -Wall -funroll-loops'
+  $CFLAGS << ' -Werror-implicit-function-declaration -Wextra -O0 -ggdb3' if ENV['DEBUG']
+end
 
 create_makefile('yajl/yajl')