diff --git a/doc/mrbgems/ruby_extension_example/Makefile b/doc/mrbgems/ruby_extension_example/Makefile
index 33eee97e9..50c99829e 100644
--- a/doc/mrbgems/ruby_extension_example/Makefile
+++ b/doc/mrbgems/ruby_extension_example/Makefile
@@ -1,7 +1,7 @@
-include ../../Makefile4gem
-
 GEM := ruby_extension_example
 
+include ../../Makefile4gem
+
 GEM_RB_FILES := $(wildcard $(MRB_DIR)/*.rb)
 
 gem-all : gem-rb-files