diff --git a/ChangeLog b/ChangeLog
index 1ba22ff3c1..f73755489b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Wed Feb 13 16:21:48 2008  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* lib/uri/generic.rb: revert r15442. 2nd argument of String#sub parse
+	  escapes. [ruby-dev:33726]
+
+	* bootstraptest/test_method.rb enc/depend instruby.rb lib/mkmf.rb
+	  mkconfig.rb: revert r15443. ditto.
+
 Wed Feb 13 11:20:26 2008  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* enc/depend: fix typo.
diff --git a/bootstraptest/test_method.rb b/bootstraptest/test_method.rb
index 2d194cdda4..8b5d584e31 100644
--- a/bootstraptest/test_method.rb
+++ b/bootstraptest/test_method.rb
@@ -657,7 +657,7 @@ C1.new.m(1,2,3,4,5,6,7,8,9)
 
 
 tests.each{|setup, methods| setup = setup.dup; setup.strip!
-  setup = BASE.gsub(/<TEST>/, setup)
+  setup = BASE.gsub(/<TEST>/){setup}
   methods.split(/\n/).each{|m| m = m.dup; m.strip!
     next if m.empty?
     expr = "#{setup}; #{m}"
diff --git a/enc/depend b/enc/depend
index 71cadde38a..d97c9056c3 100644
--- a/enc/depend
+++ b/enc/depend
@@ -46,12 +46,12 @@ $(ENCSODIR)/<%=e%>.$(DLEXT): <%=obj%>
 	echo EXPORTS > <%=df%>
 	echo <%=EXPORT_PREFIX%>Init_<%=File.basename(e)%> >> <%=df%>
 %   end
-	<%=link_so.sub(/\$\(OBJS\)/, obj).sub(/\$\(DEFFILE\)/, df.to_s).gsub(/-(?:implib|pdb):/, "\\&enc/#{e.sub(/[^\/]+\z/, '')}")%>
+	<%=link_so.sub(/\$\(OBJS\)/) {obj}.sub(/\$\(DEFFILE\)/) {df}.gsub(/-(?:implib|pdb):/) {|s|"#{s}enc/#{e.sub(/[^\/]+\z/, '')}"}%>
 
 % end
 % dependencies.each do |e|
 enc/<%=e%>.$(OBJEXT): $(srcdir)/enc/<%=e%>.c
-	<%=COMPILE_C.sub(/\$\(<(?:.*)\)/, "$(srcdir)/enc/#{e}.c")%>
+	<%=COMPILE_C.sub(/\$\(<(?:.*)\)/) {"$(srcdir)/enc/#{e}.c"}%>
 % end
 
 clean:
diff --git a/instruby.rb b/instruby.rb
index 8380df41fb..9b07951e89 100755
--- a/instruby.rb
+++ b/instruby.rb
@@ -275,7 +275,7 @@ install?(:local, :comm, :bin) do
       shebang = f.gets
       body = f.read
 
-      if shebang.sub!(/^\#!.*?ruby\b/, "#!" + ruby_shebang)
+      if shebang.sub!(/^\#!.*?ruby\b/) {"#!" + ruby_shebang}
         f.rewind
         f.print shebang, body
         f.truncate(f.pos)
diff --git a/lib/uri/generic.rb b/lib/uri/generic.rb
index 57fe0e4515..d907e0b4b2 100644
--- a/lib/uri/generic.rb
+++ b/lib/uri/generic.rb
@@ -1105,7 +1105,7 @@ module URI
 
     @@to_s = Kernel.instance_method(:to_s)
     def inspect
-      @@to_s.bind(self).call.sub!(/>\z/, " URL:#{self}>")
+      @@to_s.bind(self).call.sub!(/>\z/) {" URL:#{self}>"}
     end
 
     def coerce(oth)
diff --git a/mkconfig.rb b/mkconfig.rb
index e39307b48b..6a2eb64040 100755
--- a/mkconfig.rb
+++ b/mkconfig.rb
@@ -159,7 +159,7 @@ print <<EOS
 	config[v] = false
 	RbConfig::expand(key, config)
 	config[v] = key
-	key = key.gsub(/\#{Regexp.quote(pat)}(?=\\s|\\z)/n, sub) if pat
+	key = key.gsub(/\#{Regexp.quote(pat)}(?=\\s|\\z)/n) {sub} if pat
 	key
       else
 	var