diff --git a/Library/Homebrew/extend/os/mac/software_spec.rb b/Library/Homebrew/extend/os/mac/software_spec.rb
deleted file mode 100644
index 1be80083e2..0000000000
--- a/Library/Homebrew/extend/os/mac/software_spec.rb
+++ /dev/null
@@ -1,27 +0,0 @@
-# typed: true
-# frozen_string_literal: true
-
-# The Library/Homebrew/extend/os/software_spec.rb conditional logic will need to be more nuanced
-# if this file ever includes more than `uses_from_macos`.
-class SoftwareSpec
-  undef uses_from_macos
-
-  def uses_from_macos(deps, bounds = {})
-    if deps.is_a?(Hash)
-      bounds = deps.dup
-      deps = [bounds.shift].to_h
-    end
-
-    @uses_from_macos_elements << deps
-
-    bounds = bounds.transform_values { |v| MacOS::Version.from_symbol(v) }
-
-    # Linux simulating macOS. Assume oldest macOS version.
-    return if Homebrew::EnvConfig.simulate_macos_on_linux? && !bounds.key?(:since)
-
-    # macOS new enough for dependency to not be required.
-    return if MacOS.version >= bounds[:since]
-
-    depends_on deps
-  end
-end
diff --git a/Library/Homebrew/extend/os/software_spec.rb b/Library/Homebrew/extend/os/software_spec.rb
index 32f46468f7..1e6f8f529c 100644
--- a/Library/Homebrew/extend/os/software_spec.rb
+++ b/Library/Homebrew/extend/os/software_spec.rb
@@ -1,9 +1,4 @@
 # typed: strict
 # frozen_string_literal: true
 
-# This logic will need to be more nuanced if this file includes more than `uses_from_macos`.
-if OS.mac? || Homebrew::EnvConfig.simulate_macos_on_linux?
-  require "extend/os/mac/software_spec"
-elsif OS.linux?
-  require "extend/os/linux/software_spec"
-end
+require "extend/os/linux/software_spec" if OS.linux?
diff --git a/Library/Homebrew/software_spec.rb b/Library/Homebrew/software_spec.rb
index c27f124aa6..14825ce168 100644
--- a/Library/Homebrew/software_spec.rb
+++ b/Library/Homebrew/software_spec.rb
@@ -162,12 +162,25 @@ class SoftwareSpec
     add_dep_option(dep) if dep
   end
 
-  def uses_from_macos(spec, _bounds = {})
-    spec = [spec.dup.shift].to_h if spec.is_a?(Hash)
+  def uses_from_macos(deps, bounds = {})
+    if deps.is_a?(Hash)
+      bounds = deps.dup
+      deps = [bounds.shift].to_h
+    end
 
-    @uses_from_macos_elements << spec
+    @uses_from_macos_elements << deps
 
-    depends_on(spec)
+    # Linux simulating macOS. Assume oldest macOS version.
+    return if Homebrew::EnvConfig.simulate_macos_on_linux? && !bounds.key?(:since)
+
+    # macOS new enough for dependency to not be required.
+    if Homebrew::SimulateSystem.treat_as_macos?
+      current_os = MacOS::Version.from_symbol(Homebrew::SimulateSystem.current_os)
+      since_os = MacOS::Version.from_symbol(bounds[:since]) if bounds.key?(:since)
+      return if current_os >= since_os
+    end
+
+    depends_on deps
   end
 
   def uses_from_macos_names
diff --git a/Library/Homebrew/test/os/mac/software_spec_spec.rb b/Library/Homebrew/test/os/mac/software_spec_spec.rb
deleted file mode 100644
index c6a72db735..0000000000
--- a/Library/Homebrew/test/os/mac/software_spec_spec.rb
+++ /dev/null
@@ -1,51 +0,0 @@
-# typed: false
-# frozen_string_literal: true
-
-require "software_spec"
-
-describe SoftwareSpec do
-  subject(:spec) { described_class.new }
-
-  describe "#uses_from_macos" do
-    before do
-      allow(OS).to receive(:mac?).and_return(true)
-      allow(OS::Mac).to receive(:version).and_return(OS::Mac::Version.from_symbol(:sierra))
-    end
-
-    it "adds a macOS dependency if the OS version meets requirements" do
-      spec.uses_from_macos("foo", since: :el_capitan)
-
-      expect(spec.deps).to be_empty
-      expect(spec.uses_from_macos_elements.first).to eq("foo")
-    end
-
-    it "doesn't add a macOS dependency if the OS version doesn't meet requirements" do
-      spec.uses_from_macos("foo", since: :high_sierra)
-
-      expect(spec.deps.first.name).to eq("foo")
-      expect(spec.uses_from_macos_elements).to eq(["foo"])
-    end
-
-    it "works with tags" do
-      spec.uses_from_macos("foo" => :build, :since => :high_sierra)
-
-      dep = spec.deps.first
-
-      expect(dep.name).to eq("foo")
-      expect(dep.tags).to include(:build)
-    end
-
-    it "doesn't add a dependency if no OS version is specified" do
-      spec.uses_from_macos("foo")
-      spec.uses_from_macos("bar" => :build)
-
-      expect(spec.deps).to be_empty
-    end
-
-    it "raises an error if passing invalid OS versions" do
-      expect {
-        spec.uses_from_macos("foo", since: :bar)
-      }.to raise_error(MacOSVersionError, "unknown or unsupported macOS version: :bar")
-    end
-  end
-end
diff --git a/Library/Homebrew/test/software_spec_spec.rb b/Library/Homebrew/test/software_spec_spec.rb
index 284cf2211a..a737088803 100644
--- a/Library/Homebrew/test/software_spec_spec.rb
+++ b/Library/Homebrew/test/software_spec_spec.rb
@@ -135,27 +135,72 @@ describe SoftwareSpec do
     end
   end
 
-  describe "#uses_from_macos" do
-    it "allows specifying dependencies", :needs_linux do
-      spec.uses_from_macos("foo")
+  describe "#uses_from_macos", :needs_linux do
+    context "when running on Linux", :needs_linux do
+      it "allows specifying dependencies" do
+        spec.uses_from_macos("foo")
 
-      expect(spec.deps.first.name).to eq("foo")
+        expect(spec.deps.first.name).to eq("foo")
+      end
+
+      it "works with tags" do
+        spec.uses_from_macos("foo" => :build)
+
+        expect(spec.deps.first.name).to eq("foo")
+        expect(spec.deps.first.tags).to include(:build)
+      end
+
+      it "ignores OS version specifications" do
+        spec.uses_from_macos("foo", since: :mojave)
+        spec.uses_from_macos("bar" => :build, :since => :mojave)
+
+        expect(spec.deps.first.name).to eq("foo")
+        expect(spec.deps.last.name).to eq("bar")
+        expect(spec.deps.last.tags).to include(:build)
+      end
     end
 
-    it "works with tags", :needs_linux do
-      spec.uses_from_macos("foo" => :build)
+    context "when running on macOS", :needs_macos do
+      before do
+        allow(OS).to receive(:mac?).and_return(true)
+        allow(OS::Mac).to receive(:version).and_return(OS::Mac::Version.from_symbol(:sierra))
+      end
 
-      expect(spec.deps.first.name).to eq("foo")
-      expect(spec.deps.first.tags).to include(:build)
-    end
+      it "adds a macOS dependency if the OS version meets requirements" do
+        spec.uses_from_macos("foo", since: :el_capitan)
 
-    it "ignores OS version specifications", :needs_linux do
-      spec.uses_from_macos("foo", since: :mojave)
-      spec.uses_from_macos("bar" => :build, :since => :mojave)
+        expect(spec.deps).to be_empty
+        expect(spec.uses_from_macos_elements.first).to eq("foo")
+      end
 
-      expect(spec.deps.first.name).to eq("foo")
-      expect(spec.deps.last.name).to eq("bar")
-      expect(spec.deps.last.tags).to include(:build)
+      it "doesn't add a macOS dependency if the OS version doesn't meet requirements" do
+        spec.uses_from_macos("foo", since: :high_sierra)
+
+        expect(spec.deps.first.name).to eq("foo")
+        expect(spec.uses_from_macos_elements).to eq(["foo"])
+      end
+
+      it "works with tags" do
+        spec.uses_from_macos("foo" => :build, :since => :high_sierra)
+
+        dep = spec.deps.first
+
+        expect(dep.name).to eq("foo")
+        expect(dep.tags).to include(:build)
+      end
+
+      it "doesn't add a dependency if no OS version is specified" do
+        spec.uses_from_macos("foo")
+        spec.uses_from_macos("bar" => :build)
+
+        expect(spec.deps).to be_empty
+      end
+
+      it "raises an error if passing invalid OS versions" do
+        expect {
+          spec.uses_from_macos("foo", since: :bar)
+        }.to raise_error(MacOSVersionError, "unknown or unsupported macOS version: :bar")
+      end
     end
   end