diff --git a/error.c b/error.c
index 4b921f99ff..075cb1dfb1 100644
--- a/error.c
+++ b/error.c
@@ -327,10 +327,39 @@ warning_write(int argc, VALUE *argv, VALUE buf)
 static VALUE
 rb_warn_m(int argc, VALUE *argv, VALUE exc)
 {
-    if (!NIL_P(ruby_verbose) && argc > 0) {
+    VALUE opts, uplevel = Qnil;
+
+    if (!NIL_P(ruby_verbose) && argc > 0 &&
+	    (argc = rb_scan_args(argc, argv, "*:", NULL, &opts)) > 0) {
 	VALUE str = argv[0];
-	if (argc > 1 || !end_with_asciichar(str, '\n')) {
-	    str = rb_str_tmp_new(0);
+	if (!NIL_P(opts)) {
+	    static ID kwds[1];
+	    if (!kwds[0]) {
+		CONST_ID(kwds[0], "uplevel");
+	    }
+	    rb_get_kwargs(opts, kwds, 0, 1, &uplevel);
+	    if (uplevel == Qundef) {
+		uplevel = Qnil;
+	    }
+	    else if (!NIL_P(uplevel)) {
+		uplevel = LONG2NUM((long)NUM2ULONG(uplevel) + 1);
+		uplevel = rb_vm_thread_backtrace_locations(1, &uplevel, GET_THREAD()->self);
+		if (!NIL_P(uplevel)) {
+		    uplevel = rb_ary_entry(uplevel, 0);
+		}
+	    }
+	}
+	if (argc > 1 || !NIL_P(uplevel) || !end_with_asciichar(str, '\n')) {
+	    if (NIL_P(uplevel)) {
+		str = rb_str_tmp_new(0);
+	    }
+	    else {
+		VALUE path;
+		path = rb_funcall(uplevel, rb_intern("path"), 0);
+		str = rb_sprintf("%s:%li: warning: ",
+		    rb_string_value_ptr(&path),
+		    NUM2LONG(rb_funcall(uplevel, rb_intern("lineno"), 0)));
+	    }
 	    RBASIC_SET_CLASS(str, rb_cWarningBuffer);
 	    rb_io_puts(argc, argv, str);
 	    RBASIC_SET_CLASS(str, rb_cString);
diff --git a/lib/cgi/core.rb b/lib/cgi/core.rb
index 1b5f7ed390..d510b80628 100644
--- a/lib/cgi/core.rb
+++ b/lib/cgi/core.rb
@@ -267,7 +267,7 @@ class CGI
   def _header_for_modruby(buf)  #:nodoc:
     request = Apache::request
     buf.scan(/([^:]+): (.+)#{EOL}/o) do |name, value|
-      warn sprintf("name:%s value:%s\n", name, value) if $DEBUG
+      $stderr.puts sprintf("name:%s value:%s\n", name, value) if $DEBUG
       case name
       when 'Set-Cookie'
         request.headers_out.add(name, value)
diff --git a/lib/cmath.rb b/lib/cmath.rb
index 4f327fd188..7dbd65e799 100644
--- a/lib/cmath.rb
+++ b/lib/cmath.rb
@@ -50,7 +50,7 @@ module CMath
     atanh
   ].each do |meth|
     define_method(meth + '!') do |*args, &block|
-      warn("CMath##{meth}! is deprecated; use CMath##{meth} or Math##{meth}") if $VERBOSE
+      warn("CMath##{meth}! is deprecated; use CMath##{meth} or Math##{meth}", uplevel: 1) if $VERBOSE
       RealMath.send(meth, *args, &block)
     end
   end
diff --git a/lib/delegate.rb b/lib/delegate.rb
index 71aff40f7f..37819a28f4 100644
--- a/lib/delegate.rb
+++ b/lib/delegate.rb
@@ -97,7 +97,7 @@ class Delegator < BasicObject
     target = self.__getobj__ {r = false}
     r &&= target.respond_to?(m, include_private)
     if r && include_private && !target.respond_to?(m, false)
-      warn "#{caller(3, 1)[0]}: delegator does not forward private method \##{m}"
+      warn "delegator does not forward private method \##{m}", uplevel: 3
       return false
     end
     r
diff --git a/lib/drb/ssl.rb b/lib/drb/ssl.rb
index 8d2724e736..45fe4f1f74 100644
--- a/lib/drb/ssl.rb
+++ b/lib/drb/ssl.rb
@@ -336,7 +336,7 @@ module DRb
       end
       self.class.new(uri, ssl, @config, true)
       rescue OpenSSL::SSL::SSLError
-        warn("#{__FILE__}:#{__LINE__}: warning: #{$!.message} (#{$!.class})") if @config[:verbose]
+        warn("#{$!.message} (#{$!.class})", uplevel: 0) if @config[:verbose]
         retry
       end
     end
diff --git a/lib/forwardable.rb b/lib/forwardable.rb
index 3662f56011..a8e5aa1d5a 100644
--- a/lib/forwardable.rb
+++ b/lib/forwardable.rb
@@ -206,7 +206,7 @@ module Forwardable
       method_call = "#{<<-"begin;"}\n#{<<-"end;".chomp}"
         begin;
           unless defined? _.#{method}
-            ::Kernel.warn "\#{caller_locations(1)[0]}: "#{mesg.dump}"\#{_.class}"'##{method}'
+            ::Kernel.warn #{mesg.dump}"\#{_.class}"'##{method}', uplevel: 1
             _#{method_call}
           else
             _.#{method}(*args, &block)
diff --git a/lib/ipaddr.rb b/lib/ipaddr.rb
index 0f3a5e2878..60f102d4e6 100644
--- a/lib/ipaddr.rb
+++ b/lib/ipaddr.rb
@@ -310,7 +310,7 @@ class IPAddr
 
   # Returns true if the ipaddr is an IPv4-compatible IPv6 address.
   def ipv4_compat?
-    warn "#{caller(1, 1)[0]}: warning: IPAddr\##{__callee__} is obsolete" if $VERBOSE
+    warn "IPAddr\##{__callee__} is obsolete", uplevel: 1 if $VERBOSE
     _ipv4_compat?
   end
 
@@ -336,7 +336,7 @@ class IPAddr
   # Returns a new ipaddr built by converting the native IPv4 address
   # into an IPv4-compatible IPv6 address.
   def ipv4_compat
-    warn "#{caller(1, 1)[0]}: warning: IPAddr\##{__callee__} is obsolete" if $VERBOSE
+    warn "IPAddr\##{__callee__} is obsolete", uplevel: 1 if $VERBOSE
     if !ipv4?
       raise InvalidAddressError, "not an IPv4 address"
     end
diff --git a/lib/irb/init.rb b/lib/irb/init.rb
index db03340a69..c50e3421ec 100644
--- a/lib/irb/init.rb
+++ b/lib/irb/init.rb
@@ -277,7 +277,7 @@ module IRB # :nodoc:
       begin
         require m
       rescue LoadError => err
-        warn err.backtrace[0] << ":#{err.class}: #{err}"
+        warn ":#{err.class}: #{err}", uplevel: 0
       end
     end
   end
diff --git a/lib/irb/locale.rb b/lib/irb/locale.rb
index df540c8cbb..b713f50e76 100644
--- a/lib/irb/locale.rb
+++ b/lib/irb/locale.rb
@@ -31,7 +31,7 @@ module IRB # :nodoc:
         if @encoding_name
           begin load 'irb/encoding_aliases.rb'; rescue LoadError; end
           if @encoding = @@legacy_encoding_alias_map[@encoding_name]
-            warn "%s is obsolete. use %s" % ["#{@lang}_#{@territory}.#{@encoding_name}", "#{@lang}_#{@territory}.#{@encoding.name}"]
+            warn(("%s is obsolete. use %s" % ["#{@lang}_#{@territory}.#{@encoding_name}", "#{@lang}_#{@territory}.#{@encoding.name}"]), uplevel: 1)
           end
           @encoding = Encoding.find(@encoding_name) rescue nil
         end
diff --git a/lib/matrix.rb b/lib/matrix.rb
index ca4424f4b1..923e716b35 100644
--- a/lib/matrix.rb
+++ b/lib/matrix.rb
@@ -1184,7 +1184,7 @@ class Matrix
   # deprecated; use Matrix#determinant
   #
   def determinant_e
-    warn "#{caller(1, 1)[0]}: warning: Matrix#determinant_e is deprecated; use #determinant"
+    warn "Matrix#determinant_e is deprecated; use #determinant", uplevel: 1
     determinant
   end
   alias det_e determinant_e
@@ -1242,7 +1242,7 @@ class Matrix
   # deprecated; use Matrix#rank
   #
   def rank_e
-    warn "#{caller(1, 1)[0]}: warning: Matrix#rank_e is deprecated; use #rank"
+    warn "Matrix#rank_e is deprecated; use #rank", uplevel: 1
     rank
   end
 
@@ -1435,17 +1435,17 @@ class Matrix
   end
 
   def elements_to_f
-    warn "#{caller(1, 1)[0]}: warning: Matrix#elements_to_f is deprecated, use map(&:to_f)"
+    warn "Matrix#elements_to_f is deprecated, use map(&:to_f)", uplevel: 1
     map(&:to_f)
   end
 
   def elements_to_i
-    warn "#{caller(1, 1)[0]}: warning: Matrix#elements_to_i is deprecated, use map(&:to_i)"
+    warn "Matrix#elements_to_i is deprecated, use map(&:to_i)", uplevel: 1
     map(&:to_i)
   end
 
   def elements_to_r
-    warn "#{caller(1, 1)[0]}: warning: Matrix#elements_to_r is deprecated, use map(&:to_r)"
+    warn "Matrix#elements_to_r is deprecated, use map(&:to_r)", uplevel: 1
     map(&:to_r)
   end
 
@@ -2098,17 +2098,17 @@ class Vector
   end
 
   def elements_to_f
-    warn "#{caller(1, 1)[0]}: warning: Vector#elements_to_f is deprecated"
+    warn "Vector#elements_to_f is deprecated", uplevel: 1
     map(&:to_f)
   end
 
   def elements_to_i
-    warn "#{caller(1, 1)[0]}: warning: Vector#elements_to_i is deprecated"
+    warn "Vector#elements_to_i is deprecated", uplevel: 1
     map(&:to_i)
   end
 
   def elements_to_r
-    warn "#{caller(1, 1)[0]}: warning: Vector#elements_to_r is deprecated"
+    warn "Vector#elements_to_r is deprecated", uplevel: 1
     map(&:to_r)
   end
 
diff --git a/lib/net/ftp.rb b/lib/net/ftp.rb
index cfd72ee4e0..a7915189bd 100644
--- a/lib/net/ftp.rb
+++ b/lib/net/ftp.rb
@@ -310,13 +310,13 @@ module Net
 
     # Obsolete
     def return_code # :nodoc:
-      $stderr.puts("warning: Net::FTP#return_code is obsolete and do nothing")
+      warn("Net::FTP#return_code is obsolete and do nothing", uplevel: 1)
       return "\n"
     end
 
     # Obsolete
     def return_code=(s) # :nodoc:
-      $stderr.puts("warning: Net::FTP#return_code= is obsolete and do nothing")
+      warn("Net::FTP#return_code= is obsolete and do nothing", uplevel: 1)
     end
 
     # Constructs a socket with +host+ and +port+.
diff --git a/lib/net/http.rb b/lib/net/http.rb
index 6aa3839011..c2d33018a2 100644
--- a/lib/net/http.rb
+++ b/lib/net/http.rb
@@ -708,7 +708,7 @@ module Net   #:nodoc:
     #   http.start { .... }
     #
     def set_debug_output(output)
-      warn 'Net::HTTP#set_debug_output called after HTTP started' if started?
+      warn 'Net::HTTP#set_debug_output called after HTTP started', uplevel: 1 if started?
       @debug_output = output
     end
 
diff --git a/lib/net/http/generic_request.rb b/lib/net/http/generic_request.rb
index 6c5ceafe61..526cc333fc 100644
--- a/lib/net/http/generic_request.rb
+++ b/lib/net/http/generic_request.rb
@@ -82,7 +82,7 @@ class Net::HTTPGenericRequest
   end
 
   def body_exist?
-    warn "Net::HTTPRequest#body_exist? is obsolete; use response_body_permitted?" if $VERBOSE
+    warn "Net::HTTPRequest#body_exist? is obsolete; use response_body_permitted?", uplevel: 1 if $VERBOSE
     response_body_permitted?
   end
 
@@ -299,7 +299,7 @@ class Net::HTTPGenericRequest
 
   def supply_default_content_type
     return if content_type()
-    warn 'net/http: warning: Content-Type did not set; using application/x-www-form-urlencoded' if $VERBOSE
+    warn 'net/http: Content-Type did not set; using application/x-www-form-urlencoded', uplevel: 1 if $VERBOSE
     set_content_type 'application/x-www-form-urlencoded'
   end
 
diff --git a/lib/net/http/header.rb b/lib/net/http/header.rb
index 3484b5b681..5c543e769d 100644
--- a/lib/net/http/header.rb
+++ b/lib/net/http/header.rb
@@ -14,9 +14,9 @@ module Net::HTTPHeader
     @header = {}
     return unless initheader
     initheader.each do |key, value|
-      warn "net/http: warning: duplicated HTTP header: #{key}" if key?(key) and $VERBOSE
+      warn "net/http: duplicated HTTP header: #{key}", uplevel: 1 if key?(key) and $VERBOSE
       if value.nil?
-        warn "net/http: warning: nil HTTP header: #{key}" if $VERBOSE
+        warn "net/http: nil HTTP header: #{key}", uplevel: 1 if $VERBOSE
       else
         @header[key.downcase] = [value.strip]
       end
diff --git a/lib/net/http/response.rb b/lib/net/http/response.rb
index ee02f4be4a..6a78272ac8 100644
--- a/lib/net/http/response.rb
+++ b/lib/net/http/response.rb
@@ -140,17 +140,17 @@ class Net::HTTPResponse
   #
 
   def response   #:nodoc:
-    warn "#{caller(1, 1)[0]}: warning: Net::HTTPResponse#response is obsolete" if $VERBOSE
+    warn "Net::HTTPResponse#response is obsolete", uplevel: 1 if $VERBOSE
     self
   end
 
   def header   #:nodoc:
-    warn "#{caller(1, 1)[0]}: warning: Net::HTTPResponse#header is obsolete" if $VERBOSE
+    warn "Net::HTTPResponse#header is obsolete", uplevel: 1 if $VERBOSE
     self
   end
 
   def read_header   #:nodoc:
-    warn "#{caller(1, 1)[0]}: warning: Net::HTTPResponse#read_header is obsolete" if $VERBOSE
+    warn "Net::HTTPResponse#read_header is obsolete", uplevel: 1 if $VERBOSE
     self
   end
 
diff --git a/lib/net/imap.rb b/lib/net/imap.rb
index bb6754c732..3d33b94fdd 100644
--- a/lib/net/imap.rb
+++ b/lib/net/imap.rb
@@ -2032,8 +2032,7 @@ module Net
       # generate a warning message to +stderr+, then return
       # the value of +subtype+.
       def media_subtype
-        $stderr.printf("warning: media_subtype is obsolete.\n")
-        $stderr.printf("         use subtype instead.\n")
+        warn("media_subtype is obsolete, use subtype instead.\n", uplevel: 1)
         return subtype
       end
     end
@@ -2060,8 +2059,7 @@ module Net
       # generate a warning message to +stderr+, then return
       # the value of +subtype+.
       def media_subtype
-        $stderr.printf("warning: media_subtype is obsolete.\n")
-        $stderr.printf("         use subtype instead.\n")
+        warn("media_subtype is obsolete, use subtype instead.\n", uplevel: 1)
         return subtype
       end
     end
@@ -2090,8 +2088,7 @@ module Net
       # generate a warning message to +stderr+, then return
       # the value of +subtype+.
       def media_subtype
-        $stderr.printf("warning: media_subtype is obsolete.\n")
-        $stderr.printf("         use subtype instead.\n")
+        warn("media_subtype is obsolete, use subtype instead.\n", uplevel: 1)
         return subtype
       end
     end
@@ -2151,8 +2148,7 @@ module Net
       # generate a warning message to +stderr+, then return
       # the value of +subtype+.
       def media_subtype
-        $stderr.printf("warning: media_subtype is obsolete.\n")
-        $stderr.printf("         use subtype instead.\n")
+        warn("media_subtype is obsolete, use subtype instead.\n", uplevel: 1)
         return subtype
       end
     end
diff --git a/lib/ostruct.rb b/lib/ostruct.rb
index 6cf0ecefc3..28890304e4 100644
--- a/lib/ostruct.rb
+++ b/lib/ostruct.rb
@@ -162,7 +162,7 @@ class OpenStruct
   end
   private :modifiable?
 
-  # ::Kernel.warn("#{caller(1, 1)[0]}: do not use OpenStruct#modifiable")
+  # ::Kernel.warn("do not use OpenStruct#modifiable", uplevel: 1)
   alias modifiable modifiable? # :nodoc:
   protected :modifiable
 
@@ -181,7 +181,7 @@ class OpenStruct
   end
   private :new_ostruct_member!
 
-  # ::Kernel.warn("#{caller(1, 1)[0]}: do not use OpenStruct#new_ostruct_member")
+  # ::Kernel.warn("do not use OpenStruct#new_ostruct_member", uplevel: 1)
   alias new_ostruct_member new_ostruct_member! # :nodoc:
   protected :new_ostruct_member
 
diff --git a/lib/rexml/cdata.rb b/lib/rexml/cdata.rb
index fe9b49b5f7..2238446dc4 100644
--- a/lib/rexml/cdata.rb
+++ b/lib/rexml/cdata.rb
@@ -58,7 +58,7 @@ module REXML
     #  c = CData.new( " Some text " )
     #  c.write( $stdout )     #->  <![CDATA[ Some text ]]>
     def write( output=$stdout, indent=-1, transitive=false, ie_hack=false )
-      Kernel.warn( "#{self.class.name}.write is deprecated" )
+      Kernel.warn( "#{self.class.name}.write is deprecated", uplevel: 1)
       indent( output, indent )
       output << START
       output << @string
diff --git a/lib/rexml/comment.rb b/lib/rexml/comment.rb
index 746af77296..822fe0d586 100644
--- a/lib/rexml/comment.rb
+++ b/lib/rexml/comment.rb
@@ -48,7 +48,7 @@ module REXML
     # ie_hack::
     #    Needed for conformity to the child API, but not used by this class.
     def write( output, indent=-1, transitive=false, ie_hack=false )
-      Kernel.warn("Comment.write is deprecated.  See REXML::Formatters")
+      Kernel.warn("Comment.write is deprecated.  See REXML::Formatters", uplevel: 1)
       indent( output, indent )
       output << START
       output << @string
diff --git a/lib/rexml/element.rb b/lib/rexml/element.rb
index a9811bcba3..ac9b10872c 100644
--- a/lib/rexml/element.rb
+++ b/lib/rexml/element.rb
@@ -710,7 +710,7 @@ module REXML
     #  doc.write( out )     #-> doc is written to the string 'out'
     #  doc.write( $stdout ) #-> doc written to the console
     def write(output=$stdout, indent=-1, transitive=false, ie_hack=false)
-      Kernel.warn("#{self.class.name}.write is deprecated.  See REXML::Formatters")
+      Kernel.warn("#{self.class.name}.write is deprecated.  See REXML::Formatters", uplevel: 1)
       formatter = if indent > -1
           if transitive
             require "rexml/formatters/transitive"
diff --git a/lib/rexml/instruction.rb b/lib/rexml/instruction.rb
index 576939ca2b..c4f65eefc1 100644
--- a/lib/rexml/instruction.rb
+++ b/lib/rexml/instruction.rb
@@ -43,7 +43,7 @@ module REXML
     # See the rexml/formatters package
     #
     def write writer, indent=-1, transitive=false, ie_hack=false
-      Kernel.warn( "#{self.class.name}.write is deprecated" )
+      Kernel.warn( "#{self.class.name}.write is deprecated", uplevel: 1)
       indent(writer, indent)
       writer << START.sub(/\\/u, '')
       writer << @target
diff --git a/lib/rexml/node.rb b/lib/rexml/node.rb
index c7a3936799..52337ade44 100644
--- a/lib/rexml/node.rb
+++ b/lib/rexml/node.rb
@@ -26,7 +26,7 @@ module REXML
     #   REXML::Formatters package for changing the output style.
     def to_s indent=nil
       unless indent.nil?
-        Kernel.warn( "#{self.class.name}.to_s(indent) parameter is deprecated" )
+        Kernel.warn( "#{self.class.name}.to_s(indent) parameter is deprecated", uplevel: 1)
         f = REXML::Formatters::Pretty.new( indent )
         f.write( self, rv = "" )
       else
diff --git a/lib/rexml/text.rb b/lib/rexml/text.rb
index 9ea8ba9df3..86269dea1e 100644
--- a/lib/rexml/text.rb
+++ b/lib/rexml/text.rb
@@ -293,7 +293,7 @@ module REXML
     # See REXML::Formatters
     #
     def write( writer, indent=-1, transitive=false, ie_hack=false )
-      Kernel.warn("#{self.class.name}.write is deprecated.  See REXML::Formatters")
+      Kernel.warn("#{self.class.name}.write is deprecated.  See REXML::Formatters", uplevel: 1)
       formatter = if indent > -1
           REXML::Formatters::Pretty.new( indent )
         else
diff --git a/lib/rss/rss.rb b/lib/rss/rss.rb
index f88bb3c1ba..db87e11ad5 100644
--- a/lib/rss/rss.rb
+++ b/lib/rss/rss.rb
@@ -596,11 +596,10 @@ EOC
 
       def #{accessor_name}=(*args)
         receiver = self.class.name
-        warn("Warning:\#{caller.first.sub(/:in `.*'\z/, '')}: " \
-             "Don't use `\#{receiver}\##{accessor_name} = XXX'/" \
+        warn("Don't use `\#{receiver}\##{accessor_name} = XXX'/" \
              "`\#{receiver}\#set_#{accessor_name}(XXX)'. " \
              "Those APIs are not sense of Ruby. " \
-             "Use `\#{receiver}\##{plural_name} << XXX' instead of them.")
+             "Use `\#{receiver}\##{plural_name} << XXX' instead of them.", uplevel: 1)
         if args.size == 1
           @#{accessor_name}.push(args[0])
         else
diff --git a/lib/tempfile.rb b/lib/tempfile.rb
index 5489ac044f..671ac7b83b 100644
--- a/lib/tempfile.rb
+++ b/lib/tempfile.rb
@@ -124,7 +124,7 @@ class Tempfile < DelegateClass(File)
   # If Tempfile.new cannot find a unique filename within a limited
   # number of tries, then it will raise an exception.
   def initialize(basename="", tmpdir=nil, mode: 0, **options)
-    warn "Tempfile.new doesn't call the given block." if block_given?
+    warn "Tempfile.new doesn't call the given block.", uplevel: 1 if block_given?
 
     @unlinked = false
     @mode = mode|File::RDWR|File::CREAT|File::EXCL
@@ -250,7 +250,7 @@ class Tempfile < DelegateClass(File)
     def call(*args)
       return if @pid != Process.pid
 
-      warn "removing #{@tmpfile.path}..." if $DEBUG
+      $stderr.puts "removing #{@tmpfile.path}..." if $DEBUG
 
       @tmpfile.close
       begin
@@ -258,7 +258,7 @@ class Tempfile < DelegateClass(File)
       rescue Errno::ENOENT
       end
 
-      warn "done" if $DEBUG
+      $stderr.puts "done" if $DEBUG
     end
   end
 
diff --git a/lib/timeout.rb b/lib/timeout.rb
index 057dd7fe68..a33bb4ce65 100644
--- a/lib/timeout.rb
+++ b/lib/timeout.rb
@@ -118,7 +118,7 @@ module Timeout
 end
 
 def timeout(*args, &block)
-  warn "#{caller_locations(1, 1)[0]}: Object##{__method__} is deprecated, use Timeout.timeout instead."
+  warn "Object##{__method__} is deprecated, use Timeout.timeout instead.", uplevel: 1
   Timeout.timeout(*args, &block)
 end
 
diff --git a/lib/uri/common.rb b/lib/uri/common.rb
index a082c2a918..764f89d810 100644
--- a/lib/uri/common.rb
+++ b/lib/uri/common.rb
@@ -100,7 +100,7 @@ module URI
     #   # => "@%3F@%21"
     #
     def escape(*arg)
-      warn "#{caller(1, 1)[0]}: warning: URI.escape is obsolete" if $VERBOSE
+      warn "URI.escape is obsolete", uplevel: 1 if $VERBOSE
       DEFAULT_PARSER.escape(*arg)
     end
     alias encode escape
@@ -132,7 +132,7 @@ module URI
     #   # => "http://example.com/?a=\t\r"
     #
     def unescape(*arg)
-      warn "#{caller(1, 1)[0]}: warning: URI.unescape is obsolete" if $VERBOSE
+      warn "URI.unescape is obsolete", uplevel: 1 if $VERBOSE
       DEFAULT_PARSER.unescape(*arg)
     end
     alias decode unescape
@@ -300,7 +300,7 @@ module URI
   #   # => ["http://foo.example.com/bla", "mailto:test@example.com"]
   #
   def self.extract(str, schemes = nil, &block)
-    warn "#{caller(1, 1)[0]}: warning: URI.extract is obsolete" if $VERBOSE
+    warn "URI.extract is obsolete", uplevel: 1 if $VERBOSE
     DEFAULT_PARSER.extract(str, schemes, &block)
   end
 
@@ -336,7 +336,7 @@ module URI
   #   end
   #
   def self.regexp(schemes = nil)
-    warn "#{caller(1, 1)[0]}: warning: URI.regexp is obsolete" if $VERBOSE
+    warn "URI.regexp is obsolete", uplevel: 1 if $VERBOSE
     DEFAULT_PARSER.make_regexp(schemes)
   end
 
diff --git a/lib/uri/generic.rb b/lib/uri/generic.rb
index 044d408f50..dc4f9c4c30 100644
--- a/lib/uri/generic.rb
+++ b/lib/uri/generic.rb
@@ -1517,7 +1517,7 @@ module URI
       elsif name == 'http_proxy'
         unless proxy_uri = env[name]
           if proxy_uri = env[name.upcase]
-            warn 'The environment variable HTTP_PROXY is discouraged.  Use http_proxy.'
+            warn 'The environment variable HTTP_PROXY is discouraged.  Use http_proxy.', uplevel: 1
           end
         end
       else
diff --git a/lib/webrick/server.rb b/lib/webrick/server.rb
index 06b7f9fde3..88e160d981 100644
--- a/lib/webrick/server.rb
+++ b/lib/webrick/server.rb
@@ -103,7 +103,7 @@ module WEBrick
       @shutdown_pipe = nil
       unless @config[:DoNotListen]
         if @config[:Listen]
-          warn(":Listen option is deprecated; use GenericServer#listen")
+          warn(":Listen option is deprecated; use GenericServer#listen", uplevel: 1)
         end
         listen(@config[:BindAddress], @config[:Port])
         if @config[:Port] == 0
diff --git a/lib/webrick/utils.rb b/lib/webrick/utils.rb
index 68833af96e..07044876b9 100644
--- a/lib/webrick/utils.rb
+++ b/lib/webrick/utils.rb
@@ -37,7 +37,7 @@ module WEBrick
         Process::Sys::setgid(pw.gid)
         Process::Sys::setuid(pw.uid)
       else
-        warn("WEBrick::Utils::su doesn't work on this platform")
+        warn("WEBrick::Utils::su doesn't work on this platform", uplevel: 1)
       end
     end
     module_function :su
diff --git a/lib/yaml.rb b/lib/yaml.rb
index 0c33305e1d..aa0a1eb470 100644
--- a/lib/yaml.rb
+++ b/lib/yaml.rb
@@ -5,9 +5,9 @@
 begin
   require 'psych'
 rescue LoadError
-  warn "#{caller[0]}:"
-  warn "It seems your ruby installation is missing psych (for YAML output)."
-  warn "To eliminate this warning, please install libyaml and reinstall your ruby."
+  warn "It seems your ruby installation is missing psych (for YAML output).\n" \
+    "To eliminate this warning, please install libyaml and reinstall your ruby.\n",
+    uplevel: 1
   raise
 end
 
diff --git a/test/ruby/test_exception.rb b/test/ruby/test_exception.rb
index da1cbd37cf..ce3e98f2c8 100644
--- a/test/ruby/test_exception.rb
+++ b/test/ruby/test_exception.rb
@@ -1003,6 +1003,11 @@ $stderr = $stdout; raise "\x82\xa0"') do |outs, errs, status|
     assert_equal(["\n"],     capture_warning_warn {warn ""})
   end
 
+  def test_kernel_warn_uplevel
+    warning = capture_warning_warn {warn("test warning", uplevel: 0)}
+    assert_equal("#{__FILE__}:#{__LINE__-1}: warning: test warning\n", warning[0])
+  end
+
   def test_warning_warn_invalid_argument
     assert_raise(TypeError) do
       ::Warning.warn nil