diff --git a/Library/Homebrew/cmd/cat.rb b/Library/Homebrew/cmd/cat.rb
index a87eba61e4..ddd66922a6 100644
--- a/Library/Homebrew/cmd/cat.rb
+++ b/Library/Homebrew/cmd/cat.rb
@@ -4,6 +4,7 @@ module Homebrew extend self
     # unparsable, if the user wants to cat multiple formula they can call
     # brew cat multiple times.
 
+    raise FormulaUnspecifiedError if ARGV.named.empty?
     cd HOMEBREW_REPOSITORY
     exec "cat", ARGV.formulae.first.path, *ARGV.options_only
   end
diff --git a/Library/Homebrew/cmd/deps.rb b/Library/Homebrew/cmd/deps.rb
index 9bba1ef398..51f485880f 100644
--- a/Library/Homebrew/cmd/deps.rb
+++ b/Library/Homebrew/cmd/deps.rb
@@ -14,12 +14,14 @@ module Homebrew extend self
         puts "#{f.name}: #{f.deps*' '}"
       end
     elsif ARGV.include? '--tree'
+      raise FormulaUnspecifiedError if ARGV.named.empty?
       ARGV.formulae.each do |f|
         puts f
         recursive_deps_tree(f, 1)
         puts
       end
     else
+      raise FormulaUnspecifiedError if ARGV.named.empty?
       all_deps = ARGV.formulae.map{ |f| ARGV.one? ? f.deps : f.recursive_deps }.intersection
       all_deps.sort! unless ARGV.include? "-n"
       puts all_deps
diff --git a/Library/Homebrew/cmd/fetch.rb b/Library/Homebrew/cmd/fetch.rb
index 3828bf5d3c..d1627c83c6 100644
--- a/Library/Homebrew/cmd/fetch.rb
+++ b/Library/Homebrew/cmd/fetch.rb
@@ -4,6 +4,8 @@ require 'formula'
 
 module Homebrew extend self
   def fetch
+    raise FormulaUnspecifiedError if ARGV.named.empty?
+
     if ARGV.include? '--deps'
       bucket = []
       ARGV.formulae.each do |f|
diff --git a/Library/Homebrew/cmd/install.rb b/Library/Homebrew/cmd/install.rb
index 779482b7c5..5aa198f316 100644
--- a/Library/Homebrew/cmd/install.rb
+++ b/Library/Homebrew/cmd/install.rb
@@ -4,6 +4,8 @@ require 'blacklist'
 
 module Homebrew extend self
   def install
+    raise FormulaUnspecifiedError if ARGV.named.empty?
+
     ARGV.named.each do |name|
       msg = blacklisted? name
       raise "No available formula for #{name}\n#{msg}" if msg
diff --git a/Library/Homebrew/cmd/link.rb b/Library/Homebrew/cmd/link.rb
index 2d4ce32a6d..d222f3d256 100644
--- a/Library/Homebrew/cmd/link.rb
+++ b/Library/Homebrew/cmd/link.rb
@@ -1,5 +1,7 @@
 module Homebrew extend self
   def link
+    raise KegUnspecifiedError if ARGV.named.empty?
+
     ARGV.kegs.each do |keg|
       print "Linking #{keg}... "
       puts if ARGV.verbose?
diff --git a/Library/Homebrew/cmd/options.rb b/Library/Homebrew/cmd/options.rb
index e72bdb0a5d..696d4a46a0 100644
--- a/Library/Homebrew/cmd/options.rb
+++ b/Library/Homebrew/cmd/options.rb
@@ -11,6 +11,7 @@ def ff
       f.installed? or outdated.include? f.name
     end
   else
+    raise FormulaUnspecifiedError if ARGV.named.empty?
     ARGV.formulae
   end
 end
diff --git a/Library/Homebrew/cmd/test.rb b/Library/Homebrew/cmd/test.rb
index 7f828d9484..ed19fb3030 100644
--- a/Library/Homebrew/cmd/test.rb
+++ b/Library/Homebrew/cmd/test.rb
@@ -1,5 +1,7 @@
 module Homebrew extend self
   def test
+    raise KegUnspecifiedError if ARGV.named.empty?
+
     ARGV.formulae.each do |f|
       # Cannot test uninstalled formulae
       unless f.installed?
diff --git a/Library/Homebrew/cmd/uninstall.rb b/Library/Homebrew/cmd/uninstall.rb
index 7392c26b73..6f0025c487 100644
--- a/Library/Homebrew/cmd/uninstall.rb
+++ b/Library/Homebrew/cmd/uninstall.rb
@@ -2,6 +2,8 @@ require 'keg'
 
 module Homebrew extend self
   def uninstall
+    raise KegUnspecifiedError if ARGV.named.empty?
+
     unless ARGV.force?
       ARGV.kegs.each do |keg|
         puts "Uninstalling #{keg}..."
diff --git a/Library/Homebrew/cmd/unlink.rb b/Library/Homebrew/cmd/unlink.rb
index d4749ab765..bf1f137e0d 100644
--- a/Library/Homebrew/cmd/unlink.rb
+++ b/Library/Homebrew/cmd/unlink.rb
@@ -1,5 +1,7 @@
 module Homebrew extend self
   def unlink
+    raise FormulaUnspecifiedError if ARGV.named.empty?
+
     ARGV.kegs.each do |keg|
       print "Unlinking #{keg}... "
       puts "#{keg.unlink} links removed"
diff --git a/Library/Homebrew/cmd/uses.rb b/Library/Homebrew/cmd/uses.rb
index 324c3972e1..63bfb09f9e 100644
--- a/Library/Homebrew/cmd/uses.rb
+++ b/Library/Homebrew/cmd/uses.rb
@@ -7,7 +7,7 @@ require 'formula'
 
 module Homebrew extend self
   def uses
-    return if ARGV.formulae.empty?
+    raise FormulaUnspecifiedError if ARGV.named.empty?
 
     uses = Formula.all.select do |f|
       ARGV.formulae.all? do |ff|
diff --git a/Library/Homebrew/cmd/versions.rb b/Library/Homebrew/cmd/versions.rb
index 7a4c5cdf4d..e953e75f3f 100644
--- a/Library/Homebrew/cmd/versions.rb
+++ b/Library/Homebrew/cmd/versions.rb
@@ -4,6 +4,8 @@ module Homebrew extend self
   def versions
     raise "Please `brew install git` first" unless system "/usr/bin/which -s git"
 
+    raise FormulaUnspecifiedError if ARGV.named.empty?
+
     ARGV.formulae.all? do |f|
       if ARGV.include? '--compact'
         puts f.versions * " "