diff --git a/Library/Homebrew/cask/artifact/manpage.rb b/Library/Homebrew/cask/artifact/manpage.rb
index 3824296cbd..2c085154de 100644
--- a/Library/Homebrew/cask/artifact/manpage.rb
+++ b/Library/Homebrew/cask/artifact/manpage.rb
@@ -12,7 +12,7 @@ module Cask
       attr_reader :section
 
       def self.from_args(cask, source)
-        section = source.to_s[/\.([1-8]|n|l)$/, 1]
+        section = source.to_s[/\.([1-8]|n|l)(?:\.gz)?$/, 1]
 
         raise CaskInvalidError, "'#{source}' is not a valid man page name" unless section
 
diff --git a/Library/Homebrew/test/cask/artifact/manpage_spec.rb b/Library/Homebrew/test/cask/artifact/manpage_spec.rb
index 5cfacd2b2e..9a447b7d0d 100644
--- a/Library/Homebrew/test/cask/artifact/manpage_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/manpage_spec.rb
@@ -23,6 +23,8 @@ describe Cask::Artifact::Manpage, :cask do
 
     let(:source_path) { cask.staged_path.join("manpage.1") }
     let(:target_path) { cask.config.manpagedir.join("man1/manpage.1") }
+    let(:gz_source_path) { cask.staged_path.join("gzpage.1.gz") }
+    let(:gz_target_path) { cask.config.manpagedir.join("man1/gzpage.1.gz") }
 
     before do
       InstallHelper.install_without_artifacts(cask)
@@ -35,6 +37,7 @@ describe Cask::Artifact::Manpage, :cask do
         install_phase.call
 
         expect(File).to be_identical target_path, source_path
+        expect(File).to be_identical gz_target_path, gz_source_path
       end
     end
   end
diff --git a/Library/Homebrew/test/support/fixtures/cask/AppWithManpage.zip b/Library/Homebrew/test/support/fixtures/cask/AppWithManpage.zip
index 938933a1ca..0fc0ba5d3c 100644
Binary files a/Library/Homebrew/test/support/fixtures/cask/AppWithManpage.zip and b/Library/Homebrew/test/support/fixtures/cask/AppWithManpage.zip differ
diff --git a/Library/Homebrew/test/support/fixtures/cask/Casks/with-autodetected-manpage-section.rb b/Library/Homebrew/test/support/fixtures/cask/Casks/with-autodetected-manpage-section.rb
index b05174b380..00eff60a6c 100644
--- a/Library/Homebrew/test/support/fixtures/cask/Casks/with-autodetected-manpage-section.rb
+++ b/Library/Homebrew/test/support/fixtures/cask/Casks/with-autodetected-manpage-section.rb
@@ -1,9 +1,10 @@
 cask "with-autodetected-manpage-section" do
   version "1.2.3"
-  sha256 "68b7e71a2ca7585b004f52652749589941e3029ff0884e8aa3b099594e0282c0"
+  sha256 "1f078d5fbbaf44b05d0389b14a15f6704e0e5f8f663bc38153a4d685e38baad5"
 
   url "file://#{TEST_FIXTURE_DIR}/cask/AppWithManpage.zip"
   homepage "https://brew.sh/with-autodetected-manpage-section"
 
   manpage "manpage.1"
+  manpage "gzpage.1.gz"
 end