--- extconf.rb	2011-05-26 17:37:11.350616222 +0200
+++ extconf_patched.rb	2011-05-26 17:21:44.226616382 +0200
@@ -4,8 +4,8 @@
 RMAGICK_VERS = "0.0.0"
 MIN_RUBY_VERS = "1.8.5"
 MIN_RUBY_VERS_NO = MIN_RUBY_VERS.tr(".","").to_i
-MIN_IM_VERS = "6.4.9"
-MIN_IM_VERS_NO = MIN_IM_VERS.tr(".","").to_i
+MIN_IM_VERS = "6.4.9-0"
+MIN_IM_VERS_NO = MIN_IM_VERS.tr(".-","").to_i
 
 
 
@@ -140,7 +140,12 @@
 
   # Ensure minimum ImageMagick version
   unless checking_for("ImageMagick version >= #{MIN_IM_VERS}") do
-    version = `Magick-config --version`.chomp.tr(".","").to_i
+    version = `Magick-config --version`.chomp
+    if (version.include? '-')
+    	version = version.tr(".-","").to_i
+    else
+    	version = version.tr(".","").to_i * 10
+    end
     version >= MIN_IM_VERS_NO
   end
     exit_failure "Can't install RMagick #{RMAGICK_VERS}. You must have ImageMagick #{MIN_IM_VERS} or later.\n"