diff --git a/ChangeLog b/ChangeLog
index 23440b8194..e65513e521 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Nov 11 18:09:11 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* template/prelude.c.tmpl: move from tool/compile_prelude.rb and
+	  expand by generic_erb.rb.
+
 Tue Nov 11 13:01:31 2014  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* lib/rubygems/commands/contents_command.rb (files_in_default_gem):
diff --git a/common.mk b/common.mk
index 29a01b63bb..d2bab7b94f 100644
--- a/common.mk
+++ b/common.mk
@@ -115,8 +115,8 @@ ALLOBJS       = $(NORMALMAINOBJ) $(MINIOBJS) $(COMMONOBJS) $(DMYEXT)
 GOLFOBJS      = goruby.$(OBJEXT) golf_prelude.$(OBJEXT)
 
 DEFAULT_PRELUDES = $(GEM_PRELUDE)
-PRELUDE_SCRIPTS = $(srcdir)/prelude.rb $(srcdir)/enc/prelude.rb $(DEFAULT_PRELUDES)
-GEM_PRELUDE = $(srcdir)/gem_prelude.rb
+PRELUDE_SCRIPTS = prelude.rb enc/prelude.rb $(DEFAULT_PRELUDES)
+GEM_PRELUDE = gem_prelude.rb
 PRELUDES      = prelude.c miniprelude.c
 GOLFPRELUDES = golf_prelude.c
 
@@ -146,7 +146,7 @@ TESTRUN_SCRIPT = $(srcdir)/test.rb
 
 BOOTSTRAPRUBY = $(BASERUBY)
 
-COMPILE_PRELUDE = $(MINIRUBY) -I$(srcdir) $(srcdir)/tool/compile_prelude.rb
+COMPILE_PRELUDE = $(srcdir)/tool/generic_erb.rb $(srcdir)/template/prelude.c.tmpl
 
 all: showflags main docs
 
@@ -969,20 +969,23 @@ known_errors.inc: $(srcdir)/template/known_errors.inc.tmpl $(srcdir)/defs/known_
 	$(ECHO) generating $@
 	$(Q) $(BASERUBY) $(srcdir)/tool/generic_erb.rb -c -o $@ $(srcdir)/template/known_errors.inc.tmpl $(srcdir)/defs/known_errors.def
 
-$(MINIPRELUDE_C): $(srcdir)/tool/compile_prelude.rb $(srcdir)/prelude.rb
+$(MINIPRELUDE_C): $(COMPILE_PRELUDE) prelude.rb
 	$(ECHO) generating $@
-	$(Q) $(BASERUBY) -I$(srcdir) $(srcdir)/tool/compile_prelude.rb $(srcdir)/prelude.rb $@
+	$(Q) $(BASERUBY) $(srcdir)/tool/generic_erb.rb -I$(srcdir) -o $@ \
+		$(srcdir)/template/prelude.c.tmpl prelude.rb
 
-prelude.c: $(srcdir)/tool/compile_prelude.rb $(RBCONFIG) \
-	   $(srcdir)/lib/rubygems/defaults.rb \
-	   $(srcdir)/lib/rubygems/core_ext/kernel_gem.rb \
+prelude.c: $(COMPILE_PRELUDE) $(RBCONFIG) \
+	   lib/rubygems/defaults.rb \
+	   lib/rubygems/core_ext/kernel_gem.rb \
 	   $(PRELUDE_SCRIPTS) $(PREP) $(LIB_SRCS)
 	$(ECHO) generating $@
-	$(Q) $(COMPILE_PRELUDE) $(PRELUDE_SCRIPTS) $@
+	$(Q) $(MINIRUBY) $(srcdir)/tool/generic_erb.rb -I$(srcdir) -c -o $@ \
+		$(srcdir)/template/prelude.c.tmpl $(PRELUDE_SCRIPTS)
 
-golf_prelude.c: $(srcdir)/tool/compile_prelude.rb $(RBCONFIG) $(srcdir)/prelude.rb $(srcdir)/golf_prelude.rb $(PREP)
+golf_prelude.c: $(COMPILE_PRELUDE) $(RBCONFIG) golf_prelude.rb $(PREP)
 	$(ECHO) generating $@
-	$(Q) $(COMPILE_PRELUDE) $(srcdir)/golf_prelude.rb $@
+	$(Q) $(MINIRUBY) $(srcdir)/tool/generic_erb.rb -I$(srcdir) -c -o $@ \
+		$(srcdir)/template/prelude.c.tmpl golf_prelude.rb
 
 probes.dmyh: {$(srcdir)}probes.d $(srcdir)/tool/gen_dummy_probes.rb
 	$(BASERUBY) $(srcdir)/tool/gen_dummy_probes.rb $(srcdir)/probes.d > $@
diff --git a/tool/compile_prelude.rb b/template/prelude.c.tmpl
similarity index 83%
rename from tool/compile_prelude.rb
rename to template/prelude.c.tmpl
index 9113fd9fe8..e1859fd436 100644
--- a/tool/compile_prelude.rb
+++ b/template/prelude.c.tmpl
@@ -1,15 +1,11 @@
+<%
 # This file is interpreted by $(BASERUBY) and miniruby.
 # $(BASERUBY) is used for miniprelude.c.
 # miniruby is used for prelude.c.
 # Since $(BASERUBY) may be older than Ruby 1.9,
 # Ruby 1.9 feature should not be used.
 
-require 'erb'
-
 class Prelude
-  SRCDIR = File.dirname(File.dirname(__FILE__))
-  $:.unshift(SRCDIR)
-
   C_ESC = {
     "\\" => "\\\\",
     '"' => '\"',
@@ -24,27 +20,30 @@ class Prelude
     '"' + str.gsub(C_ESC_PAT) { C_ESC[$&] } + '"'
   end
   def prelude_base(filename)
-    filename[/\A#{Regexp.quote(SRCDIR)}\/(.*?)(\.rb)?\z/om, 1]
+    filename.chomp(".rb")
   end
   def prelude_name(filename)
     "<internal:" + prelude_base(filename) + ">"
   end
 
-  def initialize(preludes)
+  def initialize(init_name, preludes, vpath)
+    @init_name = init_name
     @mkconf = nil
     @have_sublib = false
     @need_ruby_prefix = false
+    @vpath = vpath
     @preludes = {}
     @mains = preludes.map {|filename| translate(filename)[0]}
-    @preludes.delete_if {|_, (_, _, lines, sub)| !sub && lines.empty?}
+    @preludes.delete_if {|_, (_, _, lines, sub)| sub && lines.empty?}
   end
 
   def translate(filename, sub = false)
     idx = @preludes[filename]
     return idx if idx
     lines = []
-    @preludes[filename] = result = [@preludes.size, filename, lines, sub]
-    File.readlines(filename).each do |line|
+    result = [@preludes.size, filename, lines, sub]
+    @vpath.foreach(filename) do |line|
+      @preludes[filename] ||= result
       line.sub!(/(?:^|\s+)\#(?:$|\s.*)/, '')
       line.gsub!(/RbConfig::CONFIG\["(\w+)"\]/) {
         key = $1
@@ -62,10 +61,10 @@ class Prelude
       }
       line.sub!(/require\s*\(?\s*(["'])(.*?)\1\)?/) do
         orig, path = $&, $2
-        path = File.join(SRCDIR, path)
-        if File.exist?(path)
+        path = translate(path, true) rescue nil
+        if path
           @have_sublib = true
-          "TMP_RUBY_PREFIX.require(#{translate(path, true)[0]})"
+          "TMP_RUBY_PREFIX.require(#{path[0]})"
         else
           orig
         end
@@ -74,12 +73,11 @@ class Prelude
     end
     result
   end
-
-  def emit(outfile)
-    @init_name = outfile[/\w+(?=_prelude.c\b)/] || 'prelude'
-    erb = ERB.new(<<'EOS', nil, '%')
+end
+Prelude.new(output && output[/\w+(?=_prelude.c\b)/] || 'prelude', ARGV, vpath).instance_eval do
+-%>
 /* -*-c-*-
- THIS FILE WAS AUTOGENERATED BY tool/compile_prelude.rb. DO NOT EDIT.
+ THIS FILE WAS AUTOGENERATED BY template/prelude.c.tmpl. DO NOT EDIT.
 
  sources: <%= @preludes.map {|n,*| prelude_base(n)}.join(', ') %>
 */
@@ -185,15 +183,4 @@ Init_<%=@init_name%>(void)
 % }
 #endif
 }
-EOS
-    tmp = erb.result(binding)
-    open(outfile, 'w'){|f|
-      f << tmp
-    }
-  end
-end
-
-preludes = ARGV.dup
-outfile = preludes.pop
-Prelude.new(preludes).emit(outfile)
-
+<%end -%>