diff --git a/Library/Homebrew/cmd/deps.rb b/Library/Homebrew/cmd/deps.rb
index 6a7348c792..a3bd2b8b58 100644
--- a/Library/Homebrew/cmd/deps.rb
+++ b/Library/Homebrew/cmd/deps.rb
@@ -75,29 +75,39 @@ module Homebrew
         raise FormulaUnspecifiedError if ARGV.named.empty?
         puts_deps_tree ARGV.formulae, !ARGV.one?
       end
+      return
     elsif mode.all?
       puts_deps Formula.sort
-    elsif ARGV.named.empty?
+      return
+    elsif !ARGV.named.empty? && mode.for_each?
+      puts_deps ARGV.formulae
+      return
+    end
+
+    @only_installed_arg = ARGV.include?("--installed") &&
+                          !ARGV.include?("--include-build") &&
+                          !ARGV.include?("--include-test") &&
+                          !ARGV.include?("--include-optional") &&
+                          !ARGV.include?("--skip-recommended")
+
+    if ARGV.named.empty?
       raise FormulaUnspecifiedError unless mode.installed?
       puts_deps Formula.installed.sort
-    elsif mode.for_each?
-      puts_deps ARGV.formulae
-    else
-      all_deps = deps_for_formulae(ARGV.formulae, !ARGV.one?, &(mode.union? ? :| : :&))
-      all_deps = condense_requirements(all_deps)
-      all_deps = all_deps.select(&:installed?) if mode.installed?
-      all_deps = all_deps.map(&method(:dep_display_name)).uniq
-      all_deps.sort! unless mode.topo_order?
-      puts all_deps
+      return
     end
+
+    all_deps = deps_for_formulae(ARGV.formulae, !ARGV.one?, &(mode.union? ? :| : :&))
+    all_deps = condense_requirements(all_deps)
+    all_deps.select!(&:installed?) if mode.installed?
+    all_deps.map!(&method(:dep_display_name))
+    all_deps.uniq!
+    all_deps.sort! unless mode.topo_order?
+    puts all_deps
   end
 
   def condense_requirements(deps)
-    if ARGV.include?("--include-requirements")
-      deps
-    else
-      deps.select { |dep| dep.is_a? Dependency }
-    end
+    return deps if ARGV.include?("--include-requirements")
+    deps.select { |dep| dep.is_a? Dependency }
   end
 
   def dep_display_name(dep)
@@ -108,27 +118,33 @@ module Homebrew
         # This shouldn't happen, but we'll put something here to help debugging
         "::#{dep.name}"
       end
+    elsif ARGV.include?("--full-name")
+      dep.to_formula.full_name
     else
-      ARGV.include?("--full-name") ? dep.to_formula.full_name : dep.name
+      dep.name
     end
+
     if ARGV.include?("--annotate")
       str = "#{str}  [build]" if dep.build?
       str = "#{str}  [test]" if dep.test?
       str = "#{str}  [optional" if dep.optional?
       str = "#{str}  [recommended]" if dep.recommended?
     end
+
     str
   end
 
   def deps_for_formula(f, recursive = false)
     includes, ignores = argv_includes_ignores(ARGV)
 
+    deps = f.runtime_dependencies if @only_installed_arg
+
     if recursive
-      deps = recursive_includes(Dependency,  f, includes, ignores)
-      reqs = recursive_includes(Requirement, f, includes, ignores)
+      deps ||= recursive_includes(Dependency,  f, includes, ignores)
+      reqs   = recursive_includes(Requirement, f, includes, ignores)
     else
-      deps = reject_ignores(f.deps, ignores, includes)
-      reqs = reject_ignores(f.requirements, ignores, includes)
+      deps ||= reject_ignores(f.deps, ignores, includes)
+      reqs   = reject_ignores(f.requirements, ignores, includes)
     end
 
     deps + reqs.to_a
@@ -142,7 +158,8 @@ module Homebrew
     formulae.each do |f|
       deps = deps_for_formula(f)
       deps = condense_requirements(deps)
-      deps = deps.sort_by(&:name).map(&method(:dep_display_name))
+      deps.sort_by!(&:name)
+      deps.map!(&method(:dep_display_name))
       puts "#{f.full_name}: #{deps.join(" ")}"
     end
   end
@@ -160,33 +177,39 @@ module Homebrew
     reqs = f.requirements
     deps = f.deps
     dependables = reqs + deps
-    dependables = dependables.reject(&:optional?) unless ARGV.include?("--include-optional")
-    dependables = dependables.reject(&:build?) unless ARGV.include?("--include-build")
-    dependables = dependables.reject(&:test?) unless ARGV.include?("--include-test")
-    dependables = dependables.reject(&:recommended?) if ARGV.include?("--skip-recommended")
+    dependables.reject!(&:optional?) unless ARGV.include?("--include-optional")
+    dependables.reject!(&:build?) unless ARGV.include?("--include-build")
+    dependables.reject!(&:test?) unless ARGV.include?("--include-test")
+    dependables.reject!(&:recommended?) if ARGV.include?("--skip-recommended")
     max = dependables.length - 1
     @dep_stack.push f.name
     dependables.each_with_index do |dep, i|
       next if !ARGV.include?("--include-requirements") && dep.is_a?(Requirement)
+
       tree_lines = if i == max
         "└──"
       else
         "├──"
       end
+
       display_s = "#{tree_lines} #{dep_display_name(dep)}"
       is_circular = @dep_stack.include?(dep.name)
       display_s = "#{display_s} (CIRCULAR DEPENDENCY)" if is_circular
       puts "#{prefix}#{display_s}"
+
       next if !recursive || is_circular
+
       prefix_addition = if i == max
         "    "
       else
         "│   "
       end
+
       if dep.is_a? Dependency
         recursive_deps_tree(Formulary.factory(dep.name), prefix + prefix_addition, true)
       end
     end
+
     @dep_stack.pop
   end
 end
diff --git a/Library/Homebrew/cmd/leaves.rb b/Library/Homebrew/cmd/leaves.rb
index ecebedbb35..ecc4394679 100644
--- a/Library/Homebrew/cmd/leaves.rb
+++ b/Library/Homebrew/cmd/leaves.rb
@@ -10,15 +10,12 @@ module Homebrew
 
   def leaves
     installed = Formula.installed.sort
-    deps_of_installed = Set.new
 
-    installed.each do |f|
-      deps = f.runtime_dependencies.map { |d| d.to_formula.full_name }
-      deps_of_installed.merge(deps)
+    deps_of_installed = installed.flat_map do |f|
+      f.runtime_dependencies.map(&:to_formula).map(&:full_name)
     end
 
-    installed.each do |f|
-      puts f.full_name unless deps_of_installed.include? f.full_name
-    end
+    leaves = installed.map(&:full_name) - deps_of_installed
+    leaves.each(&method(:puts))
   end
 end
diff --git a/Library/Homebrew/cmd/uses.rb b/Library/Homebrew/cmd/uses.rb
index 416f6e9032..98ecca0f5d 100644
--- a/Library/Homebrew/cmd/uses.rb
+++ b/Library/Homebrew/cmd/uses.rb
@@ -42,14 +42,21 @@ module Homebrew
 
     formulae = ARGV.include?("--installed") ? Formula.installed : Formula
     recursive = ARGV.flag? "--recursive"
+    only_installed_arg = ARGV.include?("--installed") &&
+                         !ARGV.include?("--include-build") &&
+                         !ARGV.include?("--include-test") &&
+                         !ARGV.include?("--include-optional") &&
+                         !ARGV.include?("--skip-recommended")
 
     includes, ignores = argv_includes_ignores(ARGV)
 
     uses = formulae.select do |f|
       used_formulae.all? do |ff|
         begin
+          deps = f.runtime_dependencies if only_installed_arg
           if recursive
-            deps = recursive_includes(Dependency, f, includes, ignores)
+            deps ||= recursive_includes(Dependency, f, includes, ignores)
+
             dep_formulae = deps.flat_map do |dep|
               begin
                 dep.to_formula
@@ -76,8 +83,8 @@ module Homebrew
 
             reqs = reqs_by_formula.map(&:last)
           else
-            deps = reject_ignores(f.deps, ignores, includes)
-            reqs = reject_ignores(f.requirements, ignores, includes)
+            deps ||= reject_ignores(f.deps, ignores, includes)
+            reqs   = reject_ignores(f.requirements, ignores, includes)
           end
 
           next true if deps.any? do |dep|
diff --git a/Library/Homebrew/diagnostic.rb b/Library/Homebrew/diagnostic.rb
index 706bb201a9..36df53794f 100644
--- a/Library/Homebrew/diagnostic.rb
+++ b/Library/Homebrew/diagnostic.rb
@@ -11,11 +11,9 @@ module Homebrew
       missing = {}
       ff.each do |f|
         missing_dependencies = f.missing_dependencies(hide: hide)
-
-        unless missing_dependencies.empty?
-          yield f.full_name, missing_dependencies if block_given?
-          missing[f.full_name] = missing_dependencies
-        end
+        next if missing_dependencies.empty?
+        yield f.full_name, missing_dependencies if block_given?
+        missing[f.full_name] = missing_dependencies
       end
       missing
     end
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index b41e5c5375..305a6398af 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -15,6 +15,7 @@ require "keg"
 require "migrator"
 require "extend/ENV"
 require "language/python"
+require "tab"
 
 # A formula provides instructions and metadata for Homebrew to install a piece
 # of software. Every Homebrew formula is a {Formula}.
@@ -438,7 +439,6 @@ class Formula
   # If at least one version of {Formula} is installed.
   # @private
   def any_version_installed?
-    require "tab"
     installed_prefixes.any? { |keg| (keg/Tab::FILENAME).file? }
   end
 
@@ -1486,7 +1486,14 @@ class Formula
 
   # Returns a list of Dependency objects that are required at runtime.
   # @private
-  def runtime_dependencies
+  def runtime_dependencies(read_from_tab: true)
+    if read_from_tab &&
+       installed_prefix.directory? &&
+       (keg = Keg.new(installed_prefix)) &&
+       (tab_deps = keg.runtime_dependencies)
+      return tab_deps.map { |d| Dependency.new d["full_name"] }.compact
+    end
+
     recursive_dependencies do |_, dependency|
       Dependency.prune if dependency.build?
       Dependency.prune if !dependency.required? && build.without?(dependency)
@@ -1497,20 +1504,9 @@ class Formula
   # installed
   def missing_dependencies(hide: nil)
     hide ||= []
-    missing_dependencies = recursive_dependencies do |dependent, dep|
-      if dep.build?
-        Dependency.prune
-      elsif dep.optional? || dep.recommended?
-        tab = Tab.for_formula(dependent)
-        Dependency.prune unless tab.with?(dep)
-      end
-    end
-
-    missing_dependencies.map!(&:to_formula)
-    missing_dependencies.select! do |d|
+    runtime_dependencies.map(&:to_formula).select do |d|
       hide.include?(d.name) || d.installed_prefixes.empty?
     end
-    missing_dependencies
   rescue FormulaUnavailableError
     []
   end
diff --git a/Library/Homebrew/keg.rb b/Library/Homebrew/keg.rb
index 2058d1e553..04c98c9556 100644
--- a/Library/Homebrew/keg.rb
+++ b/Library/Homebrew/keg.rb
@@ -102,47 +102,30 @@ class Keg
   #
   # For efficiency, we don't bother trying to get complete data.
   def self.find_some_installed_dependents(kegs)
-    # First, check in the tabs of installed Formulae.
-    kegs.each do |keg|
-      # Don't include dependencies of kegs that were in the given array.
-      dependents = keg.installed_dependents - kegs
-      dependents.map! { |d| "#{d.name} #{d.version}" }
-      return [keg], dependents if dependents.any?
-    end
-
-    # Some kegs won't have modern Tabs with the dependencies listed.
-    # In this case, fall back to Formula#missing_dependencies.
-
-    # Find formulae that didn't have dependencies saved in all of their kegs,
-    # so need them to be calculated now.
-    #
-    # This happens after the initial dependency check because it's sloooow.
-    remaining_formulae = Formula.installed.select do |f|
-      installed_kegs = f.installed_kegs
-
-      # Don't include dependencies of kegs that were in the given array.
-      next false if (installed_kegs - kegs).empty?
-
-      installed_kegs.any? { |k| Tab.for_keg(k).runtime_dependencies.nil? }
-    end
-
-    keg_names = kegs.map(&:name)
+    keg_names = kegs.select(&:optlinked?).map(&:name)
+    keg_formulae = []
     kegs_by_source = kegs.group_by do |keg|
       begin
         # First, attempt to resolve the keg to a formula
         # to get up-to-date name and tap information.
         f = keg.to_formula
+        keg_formulae << f
         [f.name, f.tap]
       rescue FormulaUnavailableError
         # If the formula for the keg can't be found,
         # fall back to the information in the tab.
-        [keg.name, Tab.for_keg(keg).tap]
+        [keg.name, keg.tab.tap]
       end
     end
 
-    remaining_formulae.each do |dependent|
-      required = dependent.missing_dependencies(hide: keg_names)
+    all_required_kegs = Set.new
+    all_dependents = []
 
+    # Don't include dependencies of kegs that were in the given array.
+    formulae_to_check = Formula.installed - keg_formulae
+
+    formulae_to_check.each do |dependent|
+      required = dependent.missing_dependencies(hide: keg_names)
       required_kegs = required.map do |f|
         f_kegs = kegs_by_source[[f.name, f.tap]]
         next unless f_kegs
@@ -150,12 +133,16 @@ class Keg
         f_kegs.sort_by(&:version).last
       end.compact
 
-      next unless required_kegs.any?
+      next if required_kegs.empty?
 
-      return required_kegs, [dependent.to_s]
+      all_required_kegs += required_kegs
+      all_dependents << dependent.to_s
     end
 
-    nil
+    return if all_required_kegs.empty?
+    return if all_dependents.empty?
+
+    [all_required_kegs.to_a, all_dependents.sort]
   end
 
   # if path is a file in a keg then this will return the containing Keg object
@@ -390,25 +377,6 @@ class Keg
     Formulary.from_keg(self)
   end
 
-  def installed_dependents
-    return [] unless optlinked?
-    tap = Tab.for_keg(self).source["tap"]
-    Keg.all.select do |keg|
-      tab = Tab.for_keg(keg)
-      next if tab.runtime_dependencies.nil?
-      tab.runtime_dependencies.any? do |dep|
-        # Resolve formula rather than directly comparing names
-        # in case of conflicts between formulae from different taps.
-        begin
-          dep_formula = Formulary.factory(dep["full_name"])
-          dep_formula == to_formula
-        rescue FormulaUnavailableError
-          next dep["full_name"] == "#{tap}/#{name}"
-        end
-      end
-    end
-  end
-
   def oldname_opt_record
     @oldname_opt_record ||= if (opt_dir = HOMEBREW_PREFIX/"opt").directory?
       opt_dir.subdirs.detect do |dir|
@@ -503,8 +471,16 @@ class Keg
     @oldname_opt_record = nil
   end
 
+  def tab
+    Tab.for_keg(self)
+  end
+
+  def runtime_dependencies
+    tab.runtime_dependencies
+  end
+
   def aliases
-    Tab.for_keg(self).aliases || []
+    tab.aliases || []
   end
 
   def optlink(mode = OpenStruct.new)
diff --git a/Library/Homebrew/linkage_checker.rb b/Library/Homebrew/linkage_checker.rb
index fb1aba067e..a33454a039 100644
--- a/Library/Homebrew/linkage_checker.rb
+++ b/Library/Homebrew/linkage_checker.rb
@@ -63,7 +63,8 @@ class LinkageChecker
       formula.build.without?(dep)
     end
     declared_deps = formula.deps.reject { |dep| filter_out.call(dep) }.map(&:name)
-    recursive_deps = keg.to_formula.runtime_dependencies.map { |dep| dep.to_formula.name }
+    runtime_deps = keg.to_formula.runtime_dependencies(read_from_tab: false)
+    recursive_deps = runtime_deps.map { |dep| dep.to_formula.name }
     declared_dep_names = declared_deps.map { |dep| dep.split("/").last }
     indirect_deps = []
     undeclared_deps = []
diff --git a/Library/Homebrew/tab.rb b/Library/Homebrew/tab.rb
index 02a7276683..7bfa2e36cd 100644
--- a/Library/Homebrew/tab.rb
+++ b/Library/Homebrew/tab.rb
@@ -17,6 +17,7 @@ class Tab < OpenStruct
   # Instantiates a Tab for a new installation of a formula.
   def self.create(formula, compiler, stdlib)
     build = formula.build
+    runtime_deps = formula.runtime_dependencies(read_from_tab: false)
     attributes = {
       "homebrew_version" => HOMEBREW_VERSION,
       "used_options" => build.used_options.as_flags,
@@ -32,7 +33,7 @@ class Tab < OpenStruct
       "compiler" => compiler,
       "stdlib" => stdlib,
       "aliases" => formula.aliases,
-      "runtime_dependencies" => formula.runtime_dependencies.map do |dep|
+      "runtime_dependencies" => runtime_deps.map do |dep|
         f = dep.to_formula
         { "full_name" => f.full_name, "version" => f.version.to_s }
       end,
@@ -185,7 +186,7 @@ class Tab < OpenStruct
       "stdlib" => nil,
       "compiler" => DevelopmentTools.default_compiler,
       "aliases" => [],
-      "runtime_dependencies" => [],
+      "runtime_dependencies" => nil,
       "source" => {
         "path" => nil,
         "tap" => nil,
diff --git a/Library/Homebrew/test/keg_spec.rb b/Library/Homebrew/test/keg_spec.rb
index 3bf1257e65..3aa5d5b211 100644
--- a/Library/Homebrew/test/keg_spec.rb
+++ b/Library/Homebrew/test/keg_spec.rb
@@ -373,29 +373,13 @@ describe Keg do
 
     let(:dependent) { setup_test_keg("bar", "1.0") }
 
-    # Test with a keg whose formula isn't known.
-    # This can happen if e.g. a formula is installed
-    # from a file path or URL.
-    specify "unknown Formula" do
-      allow(Formulary).to receive(:loader_for).and_call_original
-      alter_tab(keg) do |t|
-        t.source["tap"] = "some/tap"
-        t.source["path"] = nil
-      end
-
-      dependencies [{ "full_name" => "some/tap/foo", "version" => "1.0" }]
-      expect(keg.installed_dependents).to eq([dependent])
-      expect(described_class.find_some_installed_dependents([keg])).to eq([[keg], ["bar 1.0"]])
-
-      dependencies nil
-      # It doesn't make sense for a keg with no formula to have any dependents,
-      # so that can't really be tested.
-      expect(described_class.find_some_installed_dependents([keg])).to be nil
-    end
-
     specify "a dependency with no Tap in Tab" do
       tap_dep = setup_test_keg("baz", "1.0")
 
+      # allow tap_dep to be linked too
+      FileUtils.rm_r tap_dep/"bin"
+      tap_dep.link
+
       alter_tab(keg) { |t| t.source["tap"] = nil }
 
       dependencies nil
@@ -408,21 +392,18 @@ describe Keg do
 
     specify "no dependencies anywhere" do
       dependencies nil
-      expect(keg.installed_dependents).to be_empty
       expect(described_class.find_some_installed_dependents([keg])).to be nil
     end
 
     specify "missing Formula dependency" do
       dependencies nil
       Formula["bar"].class.depends_on "foo"
-      expect(keg.installed_dependents).to be_empty
       expect(described_class.find_some_installed_dependents([keg])).to eq([[keg], ["bar"]])
     end
 
     specify "uninstalling dependent and dependency" do
       dependencies nil
       Formula["bar"].class.depends_on "foo"
-      expect(keg.installed_dependents).to be_empty
       expect(described_class.find_some_installed_dependents([keg, dependent])).to be nil
     end
 
@@ -442,40 +423,34 @@ describe Keg do
 
     specify "empty dependencies in Tab" do
       dependencies []
-      expect(keg.installed_dependents).to be_empty
       expect(described_class.find_some_installed_dependents([keg])).to be nil
     end
 
     specify "same name but different version in Tab" do
       dependencies [{ "full_name" => "foo", "version" => "1.1" }]
-      expect(keg.installed_dependents).to eq([dependent])
-      expect(described_class.find_some_installed_dependents([keg])).to eq([[keg], ["bar 1.0"]])
+      expect(described_class.find_some_installed_dependents([keg])).to eq([[keg], ["bar"]])
     end
 
     specify "different name and same version in Tab" do
       stub_formula_name("baz")
       dependencies [{ "full_name" => "baz", "version" => keg.version.to_s }]
-      expect(keg.installed_dependents).to be_empty
       expect(described_class.find_some_installed_dependents([keg])).to be nil
     end
 
     specify "same name and version in Tab" do
       dependencies [{ "full_name" => "foo", "version" => "1.0" }]
-      expect(keg.installed_dependents).to eq([dependent])
-      expect(described_class.find_some_installed_dependents([keg])).to eq([[keg], ["bar 1.0"]])
+      expect(described_class.find_some_installed_dependents([keg])).to eq([[keg], ["bar"]])
     end
 
     specify "fallback for old versions" do
       unreliable_dependencies [{ "full_name" => "baz", "version" => "1.0" }]
       Formula["bar"].class.depends_on "foo"
-      expect(keg.installed_dependents).to be_empty
       expect(described_class.find_some_installed_dependents([keg])).to eq([[keg], ["bar"]])
     end
 
     specify "non-opt-linked" do
       keg.remove_opt_record
       dependencies [{ "full_name" => "foo", "version" => "1.0" }]
-      expect(keg.installed_dependents).to be_empty
       expect(described_class.find_some_installed_dependents([keg])).to be nil
     end
 
@@ -483,8 +458,7 @@ describe Keg do
       keg.unlink
       Formula["foo"].class.keg_only "a good reason"
       dependencies [{ "full_name" => "foo", "version" => "1.1" }] # different version
-      expect(keg.installed_dependents).to eq([dependent])
-      expect(described_class.find_some_installed_dependents([keg])).to eq([[keg], ["bar 1.0"]])
+      expect(described_class.find_some_installed_dependents([keg])).to eq([[keg], ["bar"]])
     end
   end
 end
diff --git a/Library/Homebrew/test/tab_spec.rb b/Library/Homebrew/test/tab_spec.rb
index 93ae42ce49..faf778e05e 100644
--- a/Library/Homebrew/test/tab_spec.rb
+++ b/Library/Homebrew/test/tab_spec.rb
@@ -68,7 +68,7 @@ describe Tab do
     expect(tab.tap).to be nil
     expect(tab.time).to be nil
     expect(tab.HEAD).to be nil
-    expect(tab.runtime_dependencies).to be_empty
+    expect(tab.runtime_dependencies).to be nil
     expect(tab.stable_version).to be nil
     expect(tab.devel_version).to be nil
     expect(tab.head_version).to be nil