diff --git a/lib/linguist/strategy/modeline.rb b/lib/linguist/strategy/modeline.rb
index f8d8d52a..e77597f4 100644
--- a/lib/linguist/strategy/modeline.rb
+++ b/lib/linguist/strategy/modeline.rb
@@ -1,8 +1,8 @@
 module Linguist
   module Strategy
     class Modeline
-      EmacsModeline = /-\*-\s*mode:\s*(\w+);?\s*-\*-/
-      VimModeline = /\/\*\s*vim:\s*set\s*(?:ft|filetype)=(\w+):\s*\*\//
+      EmacsModeline = /-\*-\s*mode:\s*(\w+);?\s*-\*-/i
+      VimModeline = /\/\*\s*vim:\s*set\s*(?:ft|filetype)=(\w+):\s*\*\//i
 
       # Public: Detects language based on Vim and Emacs modelines
       #
diff --git a/test/fixtures/Data/Modelines/iamphp.inc b/test/fixtures/Data/Modelines/iamphp.inc
index 14370309..9e67098e 100644
--- a/test/fixtures/Data/Modelines/iamphp.inc
+++ b/test/fixtures/Data/Modelines/iamphp.inc
@@ -1 +1 @@
-; -*- mode: php;-*-
+; -*- MoDe: PhP;-*-
diff --git a/test/fixtures/Data/Modelines/not_perl.pl b/test/fixtures/Data/Modelines/not_perl.pl
index df8e9fc5..39e38958 100644
--- a/test/fixtures/Data/Modelines/not_perl.pl
+++ b/test/fixtures/Data/Modelines/not_perl.pl
@@ -1,3 +1,3 @@
-/* vim: set filetype=prolog: */
+/* vim: set filEtype=pRoloG: */
 
 # I am Prolog