diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index c4b938ee..06973dd6 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -791,6 +791,15 @@ Perl:
   - .psgi
   - .t
 
+Powershell:
+  type: programming
+  lexer: Text only
+  aliases:
+  - posh
+  extensions:
+  - .ps1
+  - .psm1
+
 Prolog:
   type: programming
   extensions:
diff --git a/test/fixtures/hello.ps1 b/test/fixtures/hello.ps1
new file mode 100644
index 00000000..eca1e76c
--- /dev/null
+++ b/test/fixtures/hello.ps1
@@ -0,0 +1,2 @@
+# Hello world in powershell
+Write-Host 'Hello World'
\ No newline at end of file
diff --git a/test/fixtures/hello.psm1 b/test/fixtures/hello.psm1
new file mode 100644
index 00000000..3db82f01
--- /dev/null
+++ b/test/fixtures/hello.psm1
@@ -0,0 +1,5 @@
+# Hello World powershell module
+
+function hello() {
+  Write-Host 'Hello World'
+}
\ No newline at end of file
diff --git a/test/test_language.rb b/test/test_language.rb
index 7ea60124..65633741 100644
--- a/test/test_language.rb
+++ b/test/test_language.rb
@@ -105,6 +105,7 @@ class TestLanguage < Test::Unit::TestCase
     assert_equal Language['Literate Haskell'], Language.find_by_alias('lhs')
     assert_equal Language['Literate Haskell'], Language.find_by_alias('literate-haskell')
     assert_equal Language['Parrot Internal Representation'], Language.find_by_alias('pir')
+    assert_equal Language['Powershell'], Language.find_by_alias('posh')
     assert_equal Language['Puppet'], Language.find_by_alias('puppet')
     assert_equal Language['Pure Data'], Language.find_by_alias('pure-data')
     assert_equal Language['Raw token data'], Language.find_by_alias('raw')
@@ -188,6 +189,7 @@ class TestLanguage < Test::Unit::TestCase
   def test_programming
     assert_equal :programming, Language['JavaScript'].type
     assert_equal :programming, Language['Perl'].type
+    assert_equal :programming, Language['Powershell'].type
     assert_equal :programming, Language['Python'].type
     assert_equal :programming, Language['Ruby'].type
   end
@@ -240,6 +242,8 @@ class TestLanguage < Test::Unit::TestCase
     assert_equal Language['PHP'], Language.find_by_extension('php3')
     assert_equal Language['PHP'], Language.find_by_extension('php4')
     assert_equal Language['PHP'], Language.find_by_extension('php5')
+    assert_equal Language['Powershell'], Language.find_by_extension('psm1')
+    assert_equal Language['Powershell'], Language.find_by_extension('ps1')
     assert_nil Language.find_by_extension('.kt')
   end