diff --git a/components/script/dom/htmlscriptelement.rs b/components/script/dom/htmlscriptelement.rs
index ac15ef844f2..129ca0ff0a0 100644
--- a/components/script/dom/htmlscriptelement.rs
+++ b/components/script/dom/htmlscriptelement.rs
@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+use std::ascii::AsciiExt;
+
 use dom::attr::Attr;
 use dom::attr::AttrHelpers;
 use dom::bindings::codegen::Bindings::AttrBinding::AttrMethods;
@@ -216,7 +218,7 @@ impl<'a> HTMLScriptElementHelpers for JSRef<'a, HTMLScriptElement> {
             },
             Some(ref s) => {
                 debug!("script type={:s}", *s);
-                SCRIPT_JS_MIMES.contains(&s.as_slice().trim_chars(HTML_SPACE_CHARACTERS))
+                SCRIPT_JS_MIMES.contains(&s.to_ascii_lower().as_slice().trim_chars(HTML_SPACE_CHARACTERS))
             },
             None => {
                 debug!("no script type");
@@ -229,7 +231,7 @@ impl<'a> HTMLScriptElementHelpers for JSRef<'a, HTMLScriptElement> {
                     },
                     Some(ref s) => {
                         debug!("script language={:s}", *s);
-                        SCRIPT_JS_MIMES.contains(&format!("text/{}", s).as_slice())
+                        SCRIPT_JS_MIMES.contains(&format!("text/{}", s).to_ascii_lower().as_slice())
                     },
                     None => {
                         debug!("no script type or language, inferring js");
diff --git a/tests/wpt/metadata/html/semantics/scripting-1/the-script-element/script-languages-02.html.ini b/tests/wpt/metadata/html/semantics/scripting-1/the-script-element/script-languages-02.html.ini
deleted file mode 100644
index 1e6de9c769c..00000000000
--- a/tests/wpt/metadata/html/semantics/scripting-1/the-script-element/script-languages-02.html.ini
+++ /dev/null
@@ -1,86 +0,0 @@
-[script-languages-02.html]
-  type: testharness
-  [Script should run with type="APPLICATION/ECMASCRIPT"]
-    expected: FAIL
-
-  [Script should run with type="APPLICATION/JAVASCRIPT"]
-    expected: FAIL
-
-  [Script should run with type="APPLICATION/X-ECMASCRIPT"]
-    expected: FAIL
-
-  [Script should run with type="APPLICATION/X-JAVASCRIPT"]
-    expected: FAIL
-
-  [Script should run with type="TEXT/ECMASCRIPT"]
-    expected: FAIL
-
-  [Script should run with type="TEXT/JAVASCRIPT"]
-    expected: FAIL
-
-  [Script should run with type="TEXT/JAVASCRIPT1.0"]
-    expected: FAIL
-
-  [Script should run with type="TEXT/JAVASCRIPT1.1"]
-    expected: FAIL
-
-  [Script should run with type="TEXT/JAVASCRIPT1.2"]
-    expected: FAIL
-
-  [Script should run with type="TEXT/JAVASCRIPT1.3"]
-    expected: FAIL
-
-  [Script should run with type="TEXT/JAVASCRIPT1.4"]
-    expected: FAIL
-
-  [Script should run with type="TEXT/JAVASCRIPT1.5"]
-    expected: FAIL
-
-  [Script should run with type="TEXT/JSCRIPT"]
-    expected: FAIL
-
-  [Script should run with type="TEXT/LIVESCRIPT"]
-    expected: FAIL
-
-  [Script should run with type="TEXT/X-ECMASCRIPT"]
-    expected: FAIL
-
-  [Script should run with type="TEXT/X-JAVASCRIPT"]
-    expected: FAIL
-
-  [Script should run with language="ECMASCRIPT"]
-    expected: FAIL
-
-  [Script should run with language="JAVASCRIPT"]
-    expected: FAIL
-
-  [Script should run with language="JAVASCRIPT1.0"]
-    expected: FAIL
-
-  [Script should run with language="JAVASCRIPT1.1"]
-    expected: FAIL
-
-  [Script should run with language="JAVASCRIPT1.2"]
-    expected: FAIL
-
-  [Script should run with language="JAVASCRIPT1.3"]
-    expected: FAIL
-
-  [Script should run with language="JAVASCRIPT1.4"]
-    expected: FAIL
-
-  [Script should run with language="JAVASCRIPT1.5"]
-    expected: FAIL
-
-  [Script should run with language="JSCRIPT"]
-    expected: FAIL
-
-  [Script should run with language="LIVESCRIPT"]
-    expected: FAIL
-
-  [Script should run with language="X-ECMASCRIPT"]
-    expected: FAIL
-
-  [Script should run with language="X-JAVASCRIPT"]
-    expected: FAIL
-