diff --git a/plugins/ruby/CMakeLists.txt b/plugins/ruby/CMakeLists.txt
index d2d4d3167..8f604e746 100644
--- a/plugins/ruby/CMakeLists.txt
+++ b/plugins/ruby/CMakeLists.txt
@@ -18,14 +18,16 @@ IF (DL_RUBY)
 ENDIF(DL_RUBY)
 
 ADD_CUSTOM_COMMAND(
-    OUTPUT ruby-autogen.rb
+    OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/ruby-autogen.rb
     COMMAND ${PERL_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/codegen.pl ${dfhack_SOURCE_DIR}/library/include/df/codegen.out.xml ${CMAKE_CURRENT_SOURCE_DIR}/ruby-autogen.rb
-    DEPENDS ${dfhack_SOURCE_DIR}/library/include/df/codegen.out.xml codegen.pl
+    DEPENDS ${dfhack_SOURCE_DIR}/library/include/df/codegen.out.xml ${CMAKE_CURRENT_SOURCE_DIR}/codegen.pl
+    COMMENT ruby-autogen.rb
 )
-ADD_CUSTOM_TARGET(ruby-autogen-rb ALL DEPENDS ruby-autogen.rb)
+ADD_CUSTOM_TARGET(ruby-autogen-rb DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/ruby-autogen.rb)
 
 include_directories("${dfhack_SOURCE_DIR}/depends/tthread")
 
 DFHACK_PLUGIN(ruby ruby.cpp LINK_LIBRARIES dfhack-tinythread)
+ADD_DEPENDENCIES(ruby ruby-autogen-rb)
 
 install(FILES ruby.rb ruby-autogen.rb ${RUBYLIB} DESTINATION ${DFHACK_LIBRARY_DESTINATION})