diff --git a/components/net/mime_classifier.rs b/components/net/mime_classifier.rs
index 3b97566f018..e9bc4ed4f4f 100644
--- a/components/net/mime_classifier.rs
+++ b/components/net/mime_classifier.rs
@@ -28,6 +28,20 @@ pub enum ApacheBugFlag {
     OFF
 }
 
+impl ApacheBugFlag {
+    /// https://mimesniff.spec.whatwg.org/#supplied-mime-type-detection-algorithm
+    pub fn from_content_type(last_raw_content_type: &[u8]) -> ApacheBugFlag {
+        if last_raw_content_type == b"text/plain"
+               || last_raw_content_type == b"text/plain; charset=ISO-8859-1"
+               || last_raw_content_type == b"text/plain; charset=iso-8859-1"
+               || last_raw_content_type == b"text/plain; charset=UTF-8" {
+            ApacheBugFlag::ON
+        } else {
+            ApacheBugFlag::OFF
+        }
+    }
+}
+
 #[derive(PartialEq)]
 pub enum NoSniffFlag {
     ON,
diff --git a/components/net/resource_thread.rs b/components/net/resource_thread.rs
index 7980f707139..e5cf4669bae 100644
--- a/components/net/resource_thread.rs
+++ b/components/net/resource_thread.rs
@@ -83,11 +83,8 @@ pub fn start_sending_sniffed_opt(start_chan: LoadConsumer, mut metadata: Metadat
         let mut check_for_apache_bug = ApacheBugFlag::OFF;
 
         if let Some(ref headers) = metadata.headers {
-            if let Some(ref raw_content_type) = headers.get_raw("content-type") {
-                if raw_content_type.len() > 0 {
-                    let last_raw_content_type = &raw_content_type[raw_content_type.len() - 1];
-                    check_for_apache_bug = apache_bug_predicate(last_raw_content_type)
-                }
+            if let Some(ref content_type) = headers.get_raw("content-type").and_then(|c| c.last()) {
+                check_for_apache_bug = ApacheBugFlag::from_content_type(content_type)
             }
             if let Some(ref raw_content_type_options) = headers.get_raw("X-content-type-options") {
                 if raw_content_type_options.iter().any(|ref opt| *opt == b"nosniff") {
@@ -113,17 +110,6 @@ pub fn start_sending_sniffed_opt(start_chan: LoadConsumer, mut metadata: Metadat
     start_sending_opt(start_chan, metadata)
 }
 
-fn apache_bug_predicate(last_raw_content_type: &[u8]) -> ApacheBugFlag {
-    if last_raw_content_type == b"text/plain"
-           || last_raw_content_type == b"text/plain; charset=ISO-8859-1"
-           || last_raw_content_type == b"text/plain; charset=iso-8859-1"
-           || last_raw_content_type == b"text/plain; charset=UTF-8" {
-        ApacheBugFlag::ON
-    } else {
-        ApacheBugFlag::OFF
-    }
-}
-
 /// For use by loaders in responding to a Load message.
 fn start_sending_opt(start_chan: LoadConsumer, metadata: Metadata) -> Result<ProgressSender, ()> {
     match start_chan {