diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 9ffa068..f78323e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -7,7 +7,7 @@ jobs:
     uses: ruby/actions/.github/workflows/ruby_versions.yml@master
     with:
       engine: cruby
-      min_version: 2.6
+      min_version: 2.7
 
   test:
     needs: ruby-versions
diff --git a/lib/net/http/generic_request.rb b/lib/net/http/generic_request.rb
index d9a4c4f..5b01ea4 100644
--- a/lib/net/http/generic_request.rb
+++ b/lib/net/http/generic_request.rb
@@ -19,16 +19,13 @@ def initialize(m, reqbody, resbody, uri_or_path, initheader = nil) # :nodoc:
 
     if URI === uri_or_path then
       raise ArgumentError, "not an HTTP URI" unless URI::HTTP === uri_or_path
-      hostname = uri_or_path.hostname
+      hostname = uri_or_path.host
       raise ArgumentError, "no host component for URI" unless (hostname && hostname.length > 0)
       @uri = uri_or_path.dup
-      host = @uri.hostname.dup
-      host << ":" << @uri.port.to_s if @uri.port != @uri.default_port
       @path = uri_or_path.request_uri
       raise ArgumentError, "no HTTP request path given" unless @path
     else
       @uri = nil
-      host = nil
       raise ArgumentError, "no HTTP request path given" unless uri_or_path
       raise ArgumentError, "HTTP request path is empty" if uri_or_path.empty?
       @path = uri_or_path.dup
@@ -51,7 +48,7 @@ def initialize(m, reqbody, resbody, uri_or_path, initheader = nil) # :nodoc:
     initialize_http_header initheader
     self['Accept'] ||= '*/*'
     self['User-Agent'] ||= 'Ruby'
-    self['Host'] ||= host if host
+    self['Host'] ||= @uri.authority if @uri
     @body = nil
     @body_stream = nil
     @body_data = nil
@@ -245,7 +242,7 @@ def update_uri(addr, port, ssl) # :nodoc: internal use only
     end
 
     if host = self['host']
-      host.sub!(/:.*/m, '')
+      host = URI.parse("//#{host}").host # Remove a port component from the existing Host header
     elsif host = @uri.host
     else
      host = addr
diff --git a/net-http.gemspec b/net-http.gemspec
index e4d26c9..80e94c7 100644
--- a/net-http.gemspec
+++ b/net-http.gemspec
@@ -21,7 +21,7 @@ Gem::Specification.new do |spec|
   spec.summary       = %q{HTTP client api for Ruby.}
   spec.description   = %q{HTTP client api for Ruby.}
   spec.homepage      = "https://github.com/ruby/net-http"
-  spec.required_ruby_version = Gem::Requirement.new(">= 2.6.0")
+  spec.required_ruby_version = Gem::Requirement.new(">= 2.7.0")
   spec.licenses      = ["Ruby", "BSD-2-Clause"]
 
   spec.metadata["changelog_uri"] = spec.homepage + "/releases"
@@ -35,5 +35,5 @@ Gem::Specification.new do |spec|
   spec.bindir        = "exe"
   spec.require_paths = ["lib"]
 
-  spec.add_dependency "uri"
+  spec.add_dependency "uri", ">= 0.11.1"
 end
diff --git a/test/net/http/test_http_request.rb b/test/net/http/test_http_request.rb
index 7fd82b0..9f5cf4f 100644
--- a/test/net/http/test_http_request.rb
+++ b/test/net/http/test_http_request.rb
@@ -74,6 +74,18 @@ def test_initialize_GET_uri
     assert_equal "/foo", req.path
     assert_equal "example.com", req['Host']
 
+    req = Net::HTTP::Get.new(URI("https://203.0.113.1/foo"))
+    assert_equal "/foo", req.path
+    assert_equal "203.0.113.1", req['Host']
+
+    req = Net::HTTP::Get.new(URI("https://203.0.113.1:8000/foo"))
+    assert_equal "/foo", req.path
+    assert_equal "203.0.113.1:8000", req['Host']
+
+    req = Net::HTTP::Get.new(URI("https://[2001:db8::1]:8000/foo"))
+    assert_equal "/foo", req.path
+    assert_equal "[2001:db8::1]:8000", req['Host']
+
     assert_raise(ArgumentError){ Net::HTTP::Get.new(URI("urn:ietf:rfc:7231")) }
     assert_raise(ArgumentError){ Net::HTTP::Get.new(URI("http://")) }
   end
@@ -89,5 +101,25 @@ def test_header_set
                          'Bug #7831 - do not decode content if the user overrides'
   end if Net::HTTP::HAVE_ZLIB
 
+  def test_update_uri
+    req = Net::HTTP::Get.new(URI.parse("http://203.0.113.1"))
+    req.update_uri("test", 8080, false)
+    assert_equal "203.0.113.1", req.uri.host
+    assert_equal 8080, req.uri.port
+
+    req = Net::HTTP::Get.new(URI.parse("http://203.0.113.1:2020"))
+    req.update_uri("test", 8080, false)
+    assert_equal "203.0.113.1", req.uri.host
+    assert_equal 8080, req.uri.port
+
+    req = Net::HTTP::Get.new(URI.parse("http://[2001:db8::1]"))
+    req.update_uri("test", 8080, false)
+    assert_equal "[2001:db8::1]", req.uri.host
+    assert_equal 8080, req.uri.port
+
+    req = Net::HTTP::Get.new(URI.parse("http://[2001:db8::1]:2020"))
+    req.update_uri("test", 8080, false)
+    assert_equal "[2001:db8::1]", req.uri.host
+    assert_equal 8080, req.uri.port
+  end
 end
-